BOSTON -- Left-hander Franklin Morales, who was a useful piece for the Red Sox when he was healthy, is returning to the Colorado Rockies.
The Red Sox have acquired infielder Jonathan Herrera from the Rockies for Morales and Minor League right-hander Chris Martin.
Herrera, 29, gives Boston general manager Ben Cherington what he has been looking for -- a player who can provide depth on the left side of the infield.
The 5-foot-9, 150-pound Herrera is a switch-hitter from Venezuela and has spent his entire career with Colorado, breaking into the Majors in 2008.
Prospect acquired by Rockies
Chris Martin, rhp: Regardless of where his career takes him, it already has been an amazing ride for Martin. After turning down opportunities to sign with the Tigers (18th round, 2004) and Rockies (21st round, 2005), he tore the labrum in his throwing shoulder as a sophomore at McLennan (Texas) Community College in 2006 and figured his pitching days were done. Persuaded by a friend to attend a tryout held by the independent Grand Prairie AirHogs in 2010, Martin threw in the low 90s, got signed and was sold to the Red Sox a year later. He marched steadily through the Boston system and divided 2013 between Double-A Portland and Triple-A Pawtucket, going 5-3, 2.25 with a 74/16 K/BB ratio in 72 innings. Though he's old for a prospect at 27, Martin has size (6-foot-7) and fastball velocity (up to 96 mph) on his side. He usually pitches in the low 90s and does a good job of throwing strikes. Martin's low-80s slider is decent but nothing special, and his long arm action gives hitters a good look at the ball, which probably limits his ceiling to middle relief.
In 2013, Herrera played in 81 games and hit .292 in 195 at-bats, adding one home run, 16 RBIs and a .336 on-base percentage. He played 42 games at shortstop, including 28 starts. Herrera also started 16 games at second base and one at third last season.
Unless the Red Sox are able to re-sign free-agent shortstop Stephen Drew, they will likely open the season with Xander Bogaerts at shortstop, Will Middlebrooks at third and Herrera as a backup at both spots.
Herrera also has plenty of experience at second base, though Dustin Pedroia rarely takes a day off.
Trading Morales was made easier because the Red Sox have good depth on the left side of their bullpen, with Craig Breslow and Andrew Miller both returning next season. Drake Britton is also expected to be part of the mix.
Morales gives the Rockies an option as a starter or a reliever. His biggest problem during his time with the Red Sox was staying healthy.
Boston purchased Morales' contract from Colorado on May 19, 2011. Over three seasons, he pitched in 93 games for the Red Sox, going 6-7 with a 3.90 ERA. Morales started 10 games with Boston, including nine in 2012.
Morales had back and shoulder issues late in the 2012 season, and they carried into 2013.
In Boston's World Series-winning season, Morales pitched in 20 games during the regular season, going 2-2 with a 4.62 ERA. He made two scoreless appearances in the American League Championship Series, but did not pitch in the World Series.
Morales has pitched in seven Major League seasons, going 13-18 with a 4.38 ERA over 195 appearances.
Herrera is a .265 hitter in 984 at-bats. He has eight homers and 66 RBIs.
Martin pitched 12 times for Double-A Portland in 2013 before appearing in 30 games at Triple-A Pawtucket. He had a 2.25 ERA over those 42 games, logging 72 innings.
Ian Browne is a reporter for MLB.com. Read his blog, Brownie Points, and follow him on Twitter @IanMBrowne. This story was not subject to the approval of Major League Baseball or its clubs.