BOSTON — Aroldis Chapman hasn’t been quite the same since coming off the disabled list June 18, and Yankees pitching coach Larry Rothschild shed a little bit of light on that Saturday.

“I think he’s healthy, but I think he’s still catching up a little bit,” Rothshild said before the game against the Red Sox at Fenway Park.

Chapman, who pitched a scoreless 14th inning Saturday after blowing the save and taking the loss as the Red Sox beat the Yankees, 5-4, on Friday night, has a 3.74 ERA in 25 appearances this season. But the lefthander had a 0.79 ERA with 18 strikeouts in 11 1⁄3 innings in his first 12 games.

After allowing a combined four earned runs in 1 1⁄3 innings in his next two games, Chapman went to the DL May 14 with rotator cuff inflammation. Since being activated, he has a 4.00 ERA with 13 strikeouts and four walks in nine innings. He is not getting nearly the number of swings and misses that has typified his career, including Friday, when he faced five batters and did not record an out. (Second baseman Ronald Torreyes booted a grounder to contribute to that.)

“The quickness of the arm [is slightly different],” Rothschild said. “When it’s not quite the same, you try and generate it with your body and you get out of sync, and I’ve seen that at times. Where when he’s comfortable, he’s going to stay over the mound and the arm’s going to do a lot of the work in conjunction with the body being in the right spot at the right time.”

Chapman threw 23 pitches Friday night, all of them fastballs. That statistic jumped out to some, but that wasn’t the issue, Rothschild said. The issue was command, as only 11 of the 23 pitches were strikes.

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“You’d like to see him get ahead more. It’s commanding the fastball, obviously, which is going to be the biggest thing with him and always has been,” Rothschild said. “We have to get him more on track where it’s consistent and then he can expand the zone and you’ll see the swings and misses and things people look for out of him.”

It wasn’t as if Chapman, whose fastball reached 102 mph in the inning, was getting hammered. Mookie Betts and Dustin Pedroia reached on infield singles, and after a double steal, Torreyes butchered a grounder to allow the tying run to score. After an intentional walk to Hanley Ramirez, Chapman walked Andrew Benintendi on five pitches to force home the winning run.

For that reason, Rothschild thought it was misguided to harp on Chapman’s reliance on his fastball.

“If you’re him last night, he didn’t have a fastball squared up, so that’s your best pitch, that’s a key situation, you get behind the eight-ball a little bit, that’s what you go with,” Rothschild said. “If he gives up a home run on a slider, what are you saying today? ‘Why didn’t you throw a fastball?’ He didn’t get a ball squared up last night . . . There really weren’t good swings against him. There have been in other games, but last night, there really wasn’t.”

Much was made of Cubs manager Joe Maddon’s use — some have said overuse — of Chapman during last year’s World Series run and the possibility that some of that has carried over.

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“I really think it comes down to making better pitches and getting ahead in the count,” Joe Girardi said. “Could that be wear and tear? It’s hard to say. It really comes down to him making pitches.”