Perez, a former closer with the Cleveland Indians who was acquired to add depth to the Dodgers' bullpen, is 0-3 with a 5.03 ERA.
"We knew they were in there. We were just hoping to last as long as we could and we decided yesterday the best course of action would be to try to nip it in the bud before I couldn't even walk with it," Perez said.
The team also put left-hander Paul Maholm on the 60-day disabled list (torn knee ligament) and selected the contract of Triple-A right-hander Carlos Frias.
The latter move raises the possibility that Frias will take the rotation spot of one of the Dodgers' struggling veterans, Dan Haren or Josh Beckett, but Dodgers manager Don Mattingly said that, as of now, Frias will pitch out of the Dodgers' bullpen.
Frias, 24, went 10-5 with a 4.58 ERA in 21 games with Double-A Chattanooga and Triple-A Albuquerque combined.
"He's only a candidate to start if something happens to somebody else," Mattingly said.
Beckett met with pitching coach Rick Honeycutt and Mattingly in the manager's office before the game. Beckett, 34, has been dealing with an impingement in his left hip for about a month. He had a 2.02 ERA after his first 15 starts, but has gone 1-2 with a 6.55 ERA since and hasn't pitched as deep as the sixth inning since June 26.
Asked how Beckett was feeling Monday, the day after he went four innings and allowed three runs on six hits to the Chicago Cubs, Mattingly said, "He seems OK. Obviously, he's always a little sore, but he seems OK."