So far, the early returns on his performance have been positive. He has played 21 games since the team acquired him at the trade deadline from the Oakland Athletics in exchange for pitcher Jon Lester and outfielder Jonny Gomes. Cespedes has driven in 18 of the Sox's 79 runs since Aug. 2, which is the most RBIs on the team during that stretch.
On Sunday, Cespedes went 3-for-4, with a double, walk, RBI and two runs scored in Boston's 8-6 loss to the Seattle Mariners, which extended the Red Sox's losing skid to eight games. With the Sox trailing 7-6 and the tying run on second in the bottom of the eighth, Cespedes had an opportunity to do some damage, but he flied out to shallow left for the second out of the inning.
Even so, during this difficult stretch for the Red Sox, Cespedes has been one of the team's bright spots.
"I'm actually starting to feel real comfortable, especially getting a little more accustomed to playing here at Fenway Park," Cespedes said with the help of translator Adrian Lorenzo, who also works in the Sox's baseball operations department. "I'm feeling pretty comfortable."
A couple of things quickly stood out for Cespedes when he first arrived in Boston. The fact that the weather has been so nice this month has helped his transition.
"It's been less difficult, probably easier now that it's August and not earlier in the season when the weather isn't nice. It might have been a little more difficult then," said Cespedes, who does not like cold weather, especially having to play baseball in it.
Also, the amount of media attention in the Boston market is quite different than in Oakland.
"The first thing that struck me the most was the difference in the amount of media coverage, and just the number of reporters around in the locker room," he said. "Second, the fans. Win or lose, they're here. We're out of the race and they're here, so that's probably one of the bigger differences."
The Red Sox clubhouse will have more of a Latin flare now with Cespedes and fellow Cuban Rusney Castillo, who signed a seven-year, $72.5 million contract Saturday with the Red Sox.
The two spoke at Fenway on Saturday before Castillo's introductory media conference.
"I told him, 'This is the same game, it's the same baseball. Maybe a little better quality of baseball, but it's the same game and you don't have to try to be somebody you're not. Just be yourself and play the way you play and things will go well.' It's the same advice I give other Cubans as well," Cespedes said.
While the Red Sox hope Castillo will make his major league debut at some point in September, it may take until next season to get a better read on his abilities. But Cespedes already is a seasoned veteran.
After signing with the Athletics, Cespedes had success in the majors from the start. Fellow Cuban players Yasiel Puig and Jose Abreu joined him in making relatively smooth transitions to the big leagues.
When Red Sox general manager Ben Cherington & Co. began scouting Cespedes years ago, it was obvious he was a five-tool player. Still, there were questions about how his talents would translate at the big league level.
"I think he surprised everyone in the industry, probably with just how quickly he made the transition to the big leagues when he signed initially," Cherington said. "And we've had more examples of high-profile Cuban players come out since then, so maybe we're a little better informed now on what that transition is like. But at the time, there was an expectation there would be a little transition time and there really wasn't.
"So, he's performed, and we've only had him for a little while, but if we look at him over the three years he's been in Oakland, he's performed pretty close to where we thought his ceiling would be, it just happened quicker probably than anyone expected. We're obviously glad he's here and we're getting to know him still, he's getting comfortable here and we think he can make a big impact for us going into next year."
Cespedes is an interesting person and there's no questioning his strength.
Not only does he have the ability to hit, he's proving he can sometimes muscle a pitch to all fields, including off the Monster, which he did on Sunday for a double in the third.
What was even more impressive during Sunday's game was his underhanded flip to shortstop Brock Holt in the top of the second inning. The Mariners' Chris Taylor flied out to left field, and after Cespedes made the catch on the warning track, he flipped the ball about 150 feet directly into Holt's glove. It was an impressive show of strength and accuracy, and showed why he leads the league with14 outfield assists.
"He's done that before," Holt said. "Whenever I'm playing outfield with him, when we're warming up, he'll do his last throw like that. He can throw it pretty good like that. Obviously, we know how strong his arm is, but to be able to flick it like that, he can get it going pretty good."
Cespedes' mother, Estela, was an Olympic softball pitcher for Cuba, but Cespedes says he learned the underhand throw on his own.
"I learned it myself, kind of made it up myself," he said. "I've known how to do it for a long time, I've only started to implement it a little more this year."
Originally, the Red Sox felt Cespedes would eventually play right field, but thought it best for him to start in left field, a position he played the majority of his career with the Athletics.
Looking ahead to 2015, the Sox outfield could be jam-packed with the likes of Cespedes, Castillo, Jackie Bradley Jr., Mookie Betts, Allen Craig and Shane Victorino. If Victorino, who underwent season-ending back surgery earlier this month, is healthy for next season, he could play right and Cespedes could remain in left.
Learning how to play left field at Fenway Park will be a work in progress for Cespedes, but he's handled it pretty well so far.
"I think we all recognize that this left field is probably more challenging than any," Farrell said. "He's quickly realizing how that ball can come back into fair play that gets above the roof line and will blow back into fair territory. When we've been on the road, he's been exceptional with the range and the closing speed. Here it's going to take more games played to become familiar with that corner, particularly the wall."
Tucked away in the back of the Red Sox's clubhouse, David Ortiz sets up shop in the corner of the room. He has a few lockers of his own and has Victorino and Betts (or Bradley, depending on which prospect is up at the time) as neighbors. Only a few stalls down is Cespedes. And you can bet when Castillo eventually plays for the Red Sox, his locker will be close to Ortiz's too.
At the time the Red Sox made the deal for Cespedes, Ortiz thought it was good to add another power bat to the lineup. It bothered Ortiz that Lester was gone, but the veteran DH understands the importance of Cespedes' presence.
While he prospered in Oakland, Cespedes has a chance to thrive in Boston with Ortiz's help.
"It's been an honor and a privilege, not only to be teammates but spend time in the clubhouse and off the field," Cespedes said of Ortiz. "He's one of the great players in the game, so it's been special to me. It's an honor and a privilege."
On Thursday, Cespedes was removed from the game in the third inning against the Los Angeles Angels after his mother, who was in the stands, was transported to Massachusetts General Hospital due to high blood pressure.
Since arriving in Boston, Cespedes has credited his family for the support that has helped him become a major league player. He defected from Cuba in 2011 and became a resident in the Dominican Republic, along with 11 of his family members, including his mother.
"To me, it's one of the utmost importance because without their love and support I would've never been able to get to where I am now, both in Cuba and here," Cespedes said. "They've really helped me achieve the degree of success that I have here."