"He's kind of up and showing the ball a little bit," Callaway said. "I think that's why they're tracking him a little bit better. His stuff is there. He just has to get back to staying a little more closed, hiding the ball and keeping the ball down. When his arm slot comes up a little bit, it's harder for him to keep the ball down."
Dating back to Aug. 1, Perez has posted a 7.52 ERA and a .345 opponents' batting average across 21 appearances, leading Cleveland to pull him out of the ninth-inning job on Friday. The Indians plan on utilizing a closer-by-committee, at least through the remainder of the regular season.
When Perez returned from the disabled list in late June, following a bout with a right shoulder injury, he rattled off nine saves in nine chances and fashioned a 0.53 ERA in his first 16 games back in the bullpen. That impressive stretch came to a halt when the calendar flipped to August.
"Now, more or less it's trying to find that mix of having the velocity and still getting the ball down in the zone," Indians bullpen coach Kevin Cash said. "His slider has been, in my opinion, very good. He's thrown it a lot more, and that's probably because he just doesn't feel that he's able to be as direct with his fastball as he wants to be.
"Hopefully he'll get back in there and sort some things out."
Manager Terry Francona informed Perez that he was no longer the closer prior to Friday's game, and Francona said the reliever took the news in stride.
"He came in with a really good attitude," Francona said. "We don't take those decisions lightly, and I really respect the way he handled it. He said, 'Use me how you want.' He was really good. I don't want anybody to ever think he's backing off or anything like that, because that's not what it was."
Jordan Bastian is a reporter for MLB.com. Read his blog, Major League Bastian, and follow him on Twitter @MLBastian. This story was not subject to the approval of Major League Baseball or its clubs.