"You know, I think it's a little posture-related," said pitching coach Carl Willis. "Looking at some video when I came in, we did a little comparison of earlier on. I think, really, the last three outings now, he's just getting a little out of posture with his upper body, and it's caused him to get rotational."
Kimbrel has pitched the last two days, and three of the last four, so it's doubtful he'll be used again before the American League Division Series with the Indians starts on Thursday on TBS.
The Red Sox are a half-game behind Cleveland in the race for home-field advantage for that series. A Boston win combined with a Cleveland loss on Sunday would allow the Red Sox to get home field because they own the tiebreaker. If both teams win, home field won't be decided until the Tribe plays a makeup game against the Tigers on Monday.
Mmanager John Farrell has two other veteran relievers with closing experience -- Koji Uehara and Brad Ziegler -- but confirmed that Kimbrel will be his closer when the postseason starts.
Kimbrel feels that he will have enough time to fix what has plagued him in his last three appearances before taking the ball in the postseason.
"Absolutely, I want the ball," Kimbrel said. "The last few outings have been pretty disappointing. Nothing I can do about that. All I can really focus on is the next series and next time I get the ball."
Kimbrel had been on a roll after returning in August following surgery on his left knee. In a 16-appearance stretch from Aug. 13 to Sept. 22, he didn't allow a run and notched 23 strikeouts over 14 innings.
So what has changed the last three times out?
"Just the view from the dugout and film review, and exactly what continues to be worked on, is that he gets a little side to side," said Farrell. "And when you see the misses where he yanks to his glove side or he'll miss up and away to his arm side, he's not staying behind his arm as consistently as he has in many of his other outings. That's an area that we continue to work on as he's getting loose and [through a] throwing program, but yeah, the leadoff walk in a tie game, one-run game, those are pivotal."
In fact, Kimbrel felt he had already made some progress on Saturday, even if he's still not where he needs to be.
"I wouldn't say it's too difficult if you do it right," said Kimbrel. "You get into some bad habits when you get a little rotational. I felt like tonight I was a little better. A leadoff walk you never want to do. And a crossup led to a sac fly. Overall, I felt all right. It's just a leadoff walk and a crossup right there, and it's a run."
Mechanical adjustments are part of life for any pitcher.
"It's nothing different. I think every pitcher deals with something, a click they have to pay attention to," said Kimbrel. "I'll get it squared away. You don't have to worry about that."