Perez has a mild case of tendinitis in his right knee, but general manager Omar Minaya said that the team didn't consider putting Perez on the disabled list and that he wasn't asked to go to the Minors. As a five-year veteran, the left-hander would have to accept an assignment.
"We felt it was the right course right now," Minaya said of putting Perez in the bullpen. "I feel pretty good that Ollie is going to turn it around."
Manuel called the move a "wake-up call," with the manager adding, "I'm anxious to see how he responds."
Perez declined a request to talk with the media after being informed by Manuel and Minaya of his move to the bullpen.
Ken Takahashi, a 40-year-old veteran of the Japanese League, will take Perez's place in the rotation, with his first start scheduled for Friday night at Citi Field against Pittsburgh.
Takahashi has pitched once in relief for the Mets, allowing one hit and no runs in 2 2/3 innings Saturday against the Phillies. The left-hander started the season with Triple-A Buffalo.
"He's 5-A," Manuel said of Takahashi's place in the rotation. "If he does well, he'll be a [No. 5 starter]. If he has a lot of success, he might be [No. 3]. We lost a 3 [in Perez]."
Manuel admitted that it will be a challenge to find the right spots for Perez to pitch out of the bullpen.
"He definitely won't be the first guy [called]," Manuel said. "But you have to be cognizant of not burying him."
Manuel mentioned that he had success with starters working out their problems in the bullpen while managing the Chicago White Sox, including Jon Garland.
Mechanics are an issue with Perez.
"He doesn't quite have that same rhythm and rock [that helped him last year]," Manuel said. But a lack of confidence is the main hurdle. "I think a lot of the issues are mental, no doubt about it," the manager said.
Perez, 27, was 10-7 with the Mets last season after going 15-10 in 2007. He received his free-agent deal after the club missed out on Derek Lowe, who signed with Atlanta.
Can Perez get back on track?
"It's not uncommon for a starter to be put in the bullpen," Minaya said, though the general manager admitted that it isn't a guaranteed cure-all.