Manuel did not name a replacement for Wednesday's start against the Washington Nationals, but Perez mentioned left-hander Hisanori Takahashi by name, and a source indicated the plan is to start the Japanese left-hander in D.C.
"I don't like going to the bullpen, but I think that's the best for the team," Perez said Saturday. "I think Takahashi is pitching better than me. And right now I have trouble."
Said Manuel: "It hasn't been a good start [to the season] for him. And we have to be fair to the team. We have to do what's best for the team."
Manuel acknowledged it was internally "considered" whether Perez should be sent to the minors, but the option was never presented to Perez. The southpaw would have to approve such a move, and did not seem interested in entertaining it anyway.
"I have to do it here. Buffalo is minor leagues," Perez said. "I don't want to go there because I want to find a way to pitch better, but here. It's not the same. I've been around in this league. I know I'm better than this. I just have to keep working. I know everything is going to get better."
Perez (0-3, 5.94 ERA) is in the second season of a three-year, $36 million deal. He was pulled with one out in the fourth inning on Friday against the Florida Marlins, having allowed seven runs, including four solo homers.
Manuel suggested Perez could be available for bullpen work as soon as Sunday, on the day the left-hander would normally throw his between-starts bullpen session.
"What we'll try to do is find times to get him in where he can have some success, and then gain some confidence," Manuel said. "Obviously the responsibility is now limited. Can you give me what I need in that period? And then, maybe, I can give you a little bit more."