In that case, general manager Ben Cherington unloaded salary that he reallocated for many of the players who made up the World Series championship team last year.
This time, Cherington turned top asset Jon Lester -- who will be a free agent at season's end -- for a 28-year-old slugger in Yoenis Cespedes, who is still blossoming and could benefit from the electricity of Boston, not to mention the chance to learn from David Ortiz.
And with the trade of John Lackey, the Red Sox got two players from the Cardinals -- Allen Craig and Joe Kelly -- who are under affordable contractual control for the next several years.
After Monday's off-day, the Red Sox have 51 games left to take stock in what they have.
Here are five of the more prominent storylines to follow:
Can Jackie Bradley Jr. hit enough to play full time?
This much we've learned: Bradley is already an elite defensive center fielder who would be getting a lot more notice around the league if the Red Sox were in a better place in the standings. But the left-handed hitter had been unproductive at the plate through much of the season.
In 321 at-bats, Bradley is hitting .218/.290/.299 with only one home run. For a contending team, numbers like that would be hard to carry -- even for someone who plays defense like Bradley. He has shown glimpses of life at the plate, particularly in the days leading up to the All-Star break. Over the last few weeks of the season, Bradley needs to prove he can sustain it.
How well will Cespedes fit in Boston?
In a fairly pressure-free environment the next few weeks -- the Red Sox are no longer expected to make it to the postseason in '14 -- Cespedes can get his feet on the ground and see what kind of fit Boston is for him. Meanwhile, the Red Sox can monitor the Cuban slugger on a daily basis and see if he is the type of player they want to invest big on when he becomes a free agent following the '15 season.
Cespedes has the type of middle-of-the-order power Boston has been lacking all year. Already, the lineup has looked deeper with the outfielder a part of it. The Red Sox also want to see if Cespedes can transition to right field at Fenway, which has a lot of ground to cover. There's no question he has the arm. It will be interesting to see if playing for a franchise that stresses plate discipline will lead to any changes in the approach of the free-swinging Cespedes. An underrated aspect of Cespedes being with the Red Sox will be the chance he has to learn the ropes from Big Papi, both on and off the field.
Is Bogaerts the shortstop of the future?
After being thrust into action late last season and looking unflappable while helping the Red Sox win the World Series, Xander Bogaerts hasn't had the rookie year in '14 that people anticipated.
Though he has struggled at the plate, particularly when it comes to hitting sliders, the general expectation is that Bogaerts will hit once he gets enough experience. Defense is where Bogaerts really wants to prove himself. He started the year at short, only to be moved to third when Stephen Drew was re-acquired in late May.
One of the reasons Drew was traded last week was so Bogaerts could go back to shortstop, where he is more comfortable. The early returns the last couple of days have been encouraging, as Bogaerts has looked smooth while making all the plays. Now, he gets a chance to demonstrate how consistent he can be and whether he is a viable option at short going forward.
Can Craig get his groove back?
The right-handed hitter posted an OPS of .830 or higher from 2011-13, but has fallen off the map this season. It is indeed a red flag that Cardinals general manager John Mozeliak gave up on Craig so quickly. Then again, he got a veteran pitcher in Lackey who might help put St. Louis over the top.
One theory for Craig's lack of offense this season (a .639 OPS) is that his right foot woes from late last season prevented him from having the type of winter he's used to. Craig deserves credit for taking accountability for his struggles and not using that as an excuse.
It is at least a little concerning that he tweaked that right foot in his first game with the Red Sox and missed the ensuing two contests. The hope is that Craig can return to the lineup on Tuesday night for what figures to be an emotional rematch with the Cardinals.
Which pitchers to build around?
The trades of Lester, Lackey, Jake Peavy and Felix Doubront within a stunning span of a week leave the Red Sox with a young rotation in which only Clay Buchholz can be classified as a veteran. However, Buchholz remains the biggest enigma of all. He was one of the best pitchers in baseball the first two months of last season before suffering injuries, and he has looked lost for most of this season. Buchholz's inability to command his fastball and be able to finish off hitters has been perplexing to the pitcher and the coaching staff.
If Buchholz could get some confidence back before the season ends, that could be huge going into next year. It will also be interesting to see how Kelly -- who was having a tough year with the Cardinals -- will adapt to the American League. Kelly is only 26, and the Red Sox are confident he can emerge into an important piece of their rotation in the coming years.
Allen Webster, Rubby De La Rosa and Anthony Ranaudo are prospects who should get some reps for Boston down the stretch, and the experience could be invaluable heading into '15.