Players are graded on a 20-80 scale for future tools -- 20-30 is well below average, 40 is below average, 50 is average, 60 is above average and 70-80 is well above average.
Check out all 30 team Top 20 lists and the Top 100 on Prospect Watch.
1. Mookie Betts, 2B/OF
Preseason rank: 7
MLB Top 100 rank: 14 (Preseason: 62)
Scouting grades: Hit: 65 | Power: 45 | Run: 60 | Arm: 45 | Field: 55 | Overall: 65
A multisport star in high school, it took Betts a while to get his feet under him as a professional. He did that and more in 2013, en route to one of the biggest breakouts in the Minor Leagues. Betts has continued to progress in '14, developing into one of the best prospects in baseball and earning his first promotion to Boston.
Betts' improvement was fueled by a better approach at the plate and the introduction of power into his game. He has become a patient hitter, and he is now strong enough to drive balls into the gaps. Betts is an above-average runner, and he was one of a handful of Minor Leaguers with at least 15 home runs and 30 stolen bases in 2013.
Betts began his professional career as a shortstop, but he soon shifted to second base, where his arm profiles better. He worked to become a solid second baseman, but with Dustin Pedroia entrenched in Boston, the Red Sox are exploring ways to increase Betts' versatility. Betts began splitting his time between second base and center field in May.
2. Henry Owens, LHP
Preseason rank: 2
MLB Top 100 rank: 24 (Preseason: 30)
Scouting grades: Fastball: 60 | Curveball: 55 | Changeup: 60 | Control: 50 | Overall: 60
Owens was dinged for his perceived lack of projectability coming out of high school in 2011, but he has put those concerns to bed as a professional. After an impressive debut in '12, Owens accelerated in '13, reaching Double-A Portland, and he started the SiriusXM All-Star Futures Game for the U.S. team this year.
Owens throws his fastball in the low 90s, and it plays up, thanks to his deceptive delivery and long arms. Owens' changeup gives him a second plus pitch, and his slow curveball flashes the potential to be a third above-average offering, though it remains inconsistent.
Owens' command isn't great, and he proved to be vulnerable against left-handed hitters. But he has a good feel for pitching, giving scouts confidence he will make the adjustments necessary to reach his potential as a middle-of-the-rotation starter.
3. Blake Swihart, C
Preseason rank: 5
MLB Top 100 rank: 28 (Preseason: 61)
Scouting grades: Hit: 60 | Power: 50 | Run: 50 | Arm: 60 | Field: 50 | Overall: 60
The Red Sox were initially attracted to Swihart because of his abilities at the plate, and they believed he would develop into a good defender. He has done just that, with his defense progressing even faster than expected.
Swihart threw out 42 percent of would-be basestealers in 2013, leading the Carolina League. He has improved his game management, and he uses his athleticism well behind the plate. A switch-hitter, Swihart makes consistent hard contact from both sides of the plate. His swing is more geared for line drives now, but he projects to have average power. Swihart has toned down his aggressive approach somewhat, though he wouldn't be confused with a patient hitter. He is faster than most catchers, and he isn't a baseclogger.
Swihart is still a work in progress, but he has the potential to be an impact player in the Major Leagues.
4. Garin Cecchini, 3B
Preseason rank: 6
MLB Top 100 rank: 62 (Preseason: 57)
Scouting grades: Hit: 65 | Power: 50 | Run: 50 | Arm: 50 | Field: 50 | Overall: 55
With the injuries that plagued him at the outset of his professional career behind him, Cecchini has taken off. He has hit everywhere Boston has sent him, becoming perhaps the most consistent hitter in the system. Though Cecchini got off to a relatively slow start in Triple-A this year, scouts still love his offensive upside.
Cecchini simply finds a way to put the bat on the ball, spraying line drives to all fields. He is a very patient hitter, and he doesn't strike out much. Cecchini's frame portends him eventually developing solid power, but it isn't a big part of his game yet. He is an average runner, but his impressive instincts allow that speed to play up on the basepaths.
Cecchini is a capable third baseman and has a strong arm. The Red Sox need outfield help, so they have given him some time in left field in 2014. Cecchini's work ethic and makeup earn rave reviews, and he won the '13 Stenson Award for sportsmanship in the Arizona Fall League.
5. Allen Webster, RHP
Preseason rank: 4
MLB Top 100 rank: 64 (Preseason: 46)
Scouting grades: Fastball: 70 | Slider: 60 | Changeup: 60 | Control: 50 | Overall: 55
After mostly playing shortstop in high school, Webster developed from late-round project to top pitching prospect under the Dodgers' tutelage. He then became a key piece in the August 2012 megadeal that sent Adrian Gonzalez, Carl Crawford, Josh Beckett and Nick Punto to Los Angeles.
Webster might have the best stuff of any Red Sox prospect. His fastball sits in the mid 90s, with heavy sinking action. His changeup is his best offspeed pitch, and his slider is also an above-average offering. Webster's biggest problem is his command, especially of his two-seamer. He becomes susceptible to the long ball when his command of that pitch suffers.
Webster reached the Major Leagues in 2013, and while he struggled there, he could soon return to Boston full time if he can learn to harness his premium stuff.
6. Anthony Ranaudo, RHP
Preseason rank: 10
MLB Top 100 rank: 82 (Preseason: None)
Scouting grades: Fastball: 60 | Curveball: 60 | Changeup: 45 | Control: 50 | Overall: 55
Ranaudo had elbow issues as a freshman and junior at Louisiana State, but as a sophomore, he won the championship game of the College World Series and solidified himself as a top First-Year Player Draft prospect. Signed for $2.55 million as a supplemental first-rounder in 2010, Ranaudo had a healthy and encouraging pro debut the next year, and he seemed poised for a big '12 before a strained groin ruined that season.
Ranaudo's fastball operates at 90-96 mph, with tough sinking and boring action. His sharp curveball gives him a second plus pitch, and it hits 82 mph at times. Ranaudo tips off his changeup by slowing his delivery a bit, though it's still effective.
Ranaudo throws strikes from a high three-quarters arm slot that helps him keep his pitches down in the zone. Now that he's finally putting together back-to-back productive seasons, he's on his way to becoming a No. 2 or 3 starter.
7. Christian Vazquez, C
Preseason rank: 12
Scouting grades: Hit: 45 | Power: 40 | Run: 20 | Arm: 60 | Field: 50 | Overall: 50
Vazquez's trademark is his arm, which is one of the best among Minor League catchers. He enhances its strength with a quick transfer and release, and he led the Double-A Eastern League by erasing 47 percent of basestealers last year.
Vazquez can do more than just shut down a running game. He has some pop, and after he got too homer-conscious in 2012, he modified his approach. Vazquez focused on making contact and using the middle of the field last season, and he hit a career-high .287 with more walks (48) than strikeouts (44).
Vazquez has improved his receiving and blocking skills since turning pro, but he still has more work to do in those areas. He could hit enough to be a regular catcher in the big leagues, and if not, he should be a quality backup.
8. Rafael Devers, 3B
Preseason rank: 13
Scouting grades: Hit: 50 | Power: 60 | Run: 40 | Arm: 50 | Field: 45 | Overall: 50
Scouts rated Devers as the most advanced left-handed hitter on the international market in 2013. Signed for $1.5 million out of the Dominican Republic, Devers can put on an impressive show in batting practice. He's already capable of pulling balls out of the park, and he shows some aptitude for driving them to the opposite field.
Devers has an exceptionally quick bat, a short stroke and some feel for the strike zone. Boston is pleased that he has added strength and athleticism since turning pro, and the Red Sox like that he responds well to instruction.
An average runner now who will lose a step as he fills out, Devers will have to work to stay at third base. He shows some instincts and an average arm at the hot corner, though he needs to improve his footwork.
9. Manuel Margot, OF
Preseason rank: 11
Scouting grades: Hit: 55 | Power: 40 | Run: 65 | Arm: 50 | Field: 60 | Overall: 50
When Margot signed for $800,000 out of the Dominican Republic in 2011, he had a reputation as one of the best athletes on the international market that year. He has lived up to that billing and more than held his own as the youngest regular in the short-season New York-Penn League last year.
Margot has very quick hands and a patient approach at the plate, which, along with his well-above-average speed, should allow him to hit for high averages. A legitimate basestealing threat, Margot has the skills desired in a leadoff man. He makes consistent hard contact, and he could develop some pop if he can add strength to his lean frame.
Margot's speed plays well in center field, too, and he throws better than most players at that position. He already has skipped a level, and he could continue to advance rapidly, putting him on track to reach the Majors at age 22.
10. Edwin Escobar, LHP
Preseason rank: 2 (SF)
MLB Top 100 rank: NA (Preseason: 95)
Scouting grades: Fastball: 60 | Slider: 50 | Changeup: 50 | Control: 50 | Overall: 50
Escobar was acquired by the Giants in 2010 when he was 17 years old as compensation for allowing the Rangers to keep Rule 5 Draft selection Ben Snyder. He developed into one of San Francisco's top prospects before getting dealt to the Red Sox as part of the Jake Peavy trade in July 2014.
Escobar has a good feel for pitching, and he can add or subtract velocity and movement to his low-90s fastball as the situation requires. His slider lacks consistency at times but is an out pitch at its best. He has good feel for his changeup, giving him the potential for three average-or-better pitches.
Escobar can throw all of his pitches for strikes and isn't afraid to use them in any count. He has a solid, durable build and profiles as a middle-of-the-rotation starter.
11. Brian Johnson, LHP
Preseason rank: 14
Scouting grades: Fastball: 55 | Curveball: 55 | Cutter: 45 | Changeup: 50 | Control: 50 | Overall: 50
Johnson was a two-way star at Florida, hitting 15 homers and winning 22 games while leading the Gators to three straight College World Series from 2010-12. The 31st overall pick in the '12 Draft, Johnson signed for $1.575 million, but he had his pro debut truncated when a line drive broke multiple bones in his face during the annual Futures at Fenway event.
Johnson lost weight because he was unable to eat solid food for months, and his stuff was down at the start of 2013. But after he added strength and shook off a bout of shoulder tendinitis, he showed why the Red Sox made him a first-round pick. Johnson spotted his fastball, which sat around 91 mph and touched 94, to both sides of the plate, and he backed it up with a sharper curveball than he had thrown as an amateur.
Johnson also has a sinking changeup and a cutter in his repertoire. His command is better than he showed in his first full pro season, and it helps give him a ceiling as a No. 3 starter.
12. Deven Marrero, SS
Preseason rank: 15
Scouting grades: Hit: 45 | Power: 40 | Run: 55 | Arm: 60 | Field: 60 | Overall: 50
Once considered a potential No. 1 overall pick in the 2012 Draft, Marrero slumped as an Arizona State junior, and he fell to No. 25. A rare college shortstop who's good enough to play the position in the Majors, he signed for $2.05 million.
Marrero has lived up to his defensive billing as a pro. He's not the flashiest shortstop, but he's tremendously instinctive and fundamentally sound. Marrero's range, hands and arm are all assets, and he made just six errors in 104 games at short last year.
Marrero has yet to show much offensively in pro ball, though he has controlled the strike zone and made consistent contact. He has a leg kick that can throw his timing off, and it tends to pull off pitches, but Boston believes he can become an effective hitter and perhaps have more power than he has shown. Marrero's solid speed plays up on the bases.
13. Matt Barnes, RHP
Preseason rank: 8
Scouting grades: Fastball: 60 | Curveball: 50 | Changeup: 55 | Control: 50 | Overall: 50
Barnes began his professional career about as well as he possibly could have, and he pitched in the Futures Game just a year after being drafted. While he probably won't repeat that level of success, he has all the tools necessary to become a solid Major League starter.
Barnes throws his fastball in the mid-90s, occasionally running it up to 98 mph. He commands the pitch well, and he throws it effectively to both sides of the plate. Barnes' changeup and curveball are both solid offerings, but they have room to improve.
Barnes has quickly reached the upper levels of the Minor Leagues, joining a large group of nearly big league-ready starters in the Red Sox's system. That abundance of pitching will give Barnes the time he needs to refine his game as he progresses toward his profile of a middle-of-the-rotation starter.
14. Trey Ball, LHP
Preseason rank: 9
Scouting grades: Fastball: 60 | Curveball: 55 | Changeup: 55 | Control: 45 | Overall: 50
An excellent athlete, Ball was considered the top two-way player in the 2013 Draft class. In the end, however, scouts couldn't pass up his combination of size and stuff from the left side, and Boston selected him seventh overall as a pitcher.
Ball throws his fastball in the low 90s, and there is projection left in his lanky frame. He only began throwing a curveball a couple years ago, but it already shows the potential to be an above-average pitch. In the absence of a breaking ball, Ball's changeup blossomed, and it has the potential to develop into a plus offering.
Despite his height, Ball's athleticism gives him a chance to learn how to repeat his delivery well enough to have solid command. Though he is further away than most of the Red Sox's top pitching prospects, Ball's ceiling might be the highest of all of them.
15. Sean Coyle, 2B/3B
Preseason rank: None
Scouting grades: Hit: 50 | Power: 50 | Run: 55 | Arm: 45 | Field: 50 | Overall: 50
Boston liked Coyle's power potential and plus speed enough to give him a $1.3 million bonus as a third-round pick in 2010, but inconsistency at the plate and injuries plagued him in his first three full pro seasons. While Coyle missed three weeks in May with hamstring and hand ailments, he has been otherwise healthy and enjoying his most productive year ever, which earned him a trip to the Futures Game.
Because he's a 5-foot-8 second baseman, Coyle inevitably draws comparisons to Pedroia. While he has an aggressive approach and generates surprising pop for his size, Coyle doesn't make contact as consistently as Pedroia. Coyle is faster, however, and is an adept basestealer who succeeded on 88 percent of his first 69 pro attempts.
Coyle has good hands and enough arm strength to make plays at second base, though he's blocked by Pedroia and Betts at that position. While Coyle has seen some action at third base in 2014, his arm doesn't really fit at the hot corner.
16. Michael Chavis, SS
Preseason rank: None (2014 Draft)
Scouting grades: Hit: 55 | Power: 55 | Run: 50 | Arm: 60 | Field: 45 | Overall: 50
Chavis made a name for himself when he won the home run derby at the 2013 Perfect Game All-American Classic, beating out note prep sluggers such as Alex Jackson and Braxton Davidson. Chavis continued to rake as a high school senior, hitting himself into the first round of the '14 Draft and signing for $1,870,500 as the 26th overall pick.
Scouts who like Chavis think he'll produce for both average and power, noting that he got stronger and did a much better job covering the entire plate as a senior. Chavis consistently makes hard contact, though some evaluators wonder if he's already physically mature and how well the uppercut in his right-handed swing will play against more advanced pitching.
Though Chavis is beginning his pro career at his high school position of shortstop, he lacks the range to play there at upper levels. Some scouts believe he's quick enough to play second base, while his strong arm and power potential would profile well at third base.
17. Michael Kopech, RHP
Preseason rank: None (2014 Draft)
Scouting grades: Fastball: 65 | Slider: 60 | Changeup: 45 | Control: 45 | Overall: 50
Before the Red Sox selected Kopech 33rd overall in June, they hadn't drafted a high school right-hander in the first round since Josh Garrett in 1996. Kopech features an unusual delivery, with lots of twists and turns and some deep tilt in the back, but the stuff it produces earned him a $1.5 million bonus.
Kopech still has plenty of room to add strength to his lanky 6-foot-4 frame, and he already works in the low 90s, and he can reach 97 mph with his fastball. When Kopech stays on top of his breaking ball, it has slider power and curveball depth. He fanned Alex Jackson, the 2014 Draft's top high school position prospect, on three straight breakers at the '13 Under Armour All-America Game.
Kopech's changeup is still a work in progress, because he didn't need it much as an amateur. If Kopech can throw enough quality strikes, he has the stuff to pitch in the front half of a big league rotation.
18. Wendell Rijo, 2B
Preseason rank: 16
Scouting grades: Hit: 55 | Power: 40 | Run: 50 | Arm: 45 | Field: 55 | Overall: 45
Rijo is extremely polished for his age, in large part because he grew up around the game as the son of Dodgers scout Rafael Rijo. Wendell tore the ACL in his right knee in March 2012, four months before he became eligible to sign, but that didn't stop Boston from inking him for $575,000. Sent to the Rookie-level Gulf Coast League at age 17, Wendell had a solid debut last summer, despite being one of the youngest regulars in the league.
Rijo has the bat speed and already-mature approach to hit for average, and he could have double-digit home run power as he gets stronger. Rijo can get off balance at the plate from time to time, but that's a correctable flaw.
While Rijo isn't as fast as he was prior to knee surgery, he still has average speed, and he knows what he's doing on the bases. Rijo's instincts shine as well on defense, where he has sure hands, but he lacks the arm strength to play on the left side of the diamond.
19. Simon Mercedes, RHP
Preseason rank: None
Scouting grades: Fastball: 70 | Curveball: 55 | Changeup: 45 | Control: 55 | Overall: 45
The Red Sox have both been burned by and benefited from MLB investigations into the identities of Latin American pitchers. They originally signed Carlos Martinez for $160,000 in 2009, but they didn't have him cleared by MLB, and they saw him go to the Cardinals for $1.5 million. Conversely, the Giants signed Mercedes for $400,000 in '11, only to see him run afoul of MLB and land with Boston for $800,000 a year later.
One of the hardest throwers in the system, Mercedes hit 100 mph during a dazzling Spring Training. After working mostly at 92-95 mph, he's showing more velocity more consistently this year, now that he's recovered from an injury to his right middle finger that plagued him in 2013. Mercedes is also snapping off more impressive power breaking balls, now that he's healthy.
Mercedes throws strikes with three pitches, giving him a chance to make it as a big league starter, if he can refine his changeup. With Mercedes' power repertoire, he also has the makings of a late-inning relief option.
20. Travis Shaw, 1B/3B
Preseason rank: 21
Scouting grades: Hit: 40 | Power: 55 | Run: 30 | Arm: 50 | Field: 45 | Overall: 45
The Red Sox originally drafted Shaw in the 32nd round of the 2008 Draft, but he chose to go to Kent State. Three years later, Boston got its man in the ninth round, and Shaw has been a steady performer in the Minor Leagues.
Shaw has a smooth swing and a patient approach. He has solid power, and he hit at least 16 home runs in each of his first two full professional seasons. A third baseman in college who still sees sporadic action at the hot corner, he isn't very athletic, but he has good hands, and he is a capable first baseman.
Shaw's father, Jeff Shaw, is a former All-Star closer, and Travis has a good understanding of the game as a result. That should serve him well as he advances toward Boston.