LOS ANGELES -- The Dodgers have problems in the back end of their rotation, and a short-term solution may have just joined the team. The team on Monday placed relief pitcher Chris Perez on the 15-day disabled list with bone spurs in his right ankle, and recalled Carlos Frias from Triple-A Albuquerque.

Frias was originally scheduled to start for the Isotopes on Monday night, and would in theory be ready to start on Wednesday. But manager Don Mattingly repeated what he said over the weekend, that Dan Haren, 0-5 with a 10.03 ERA in his last five starts, would make his scheduled start on Wednesday.

Mattingly also reiterated that Josh Beckett would start Friay, and that Frias would pitch out of the bullpen.

"[Frias] gives us a guy who is stretched out to start, and can give us length in the bullpen," Mattingly said. "He would only be a candidate [to start] if something happens to somebody else."

Frias was 8-4 with a 5.01 ERA in 16 games, including 15 starts, for Albuquerque, with 65 strikeouts and 21 walks in 91⅔ innings. He has pitched only nine games in relief in the last three seasons, but said he gained bullpen experience in winter ball.

"I've pitched in relief before," Frias said. "You've got to be ready, man."

Frias, 24, has only allowed four home runs in the hitter friendly Pacific Coast League. He thrives on keeping the ball down and inducing ground balls. His 46.3-percent ground ball rate ranks 31st among the 109 PCL pitchers with at least 50 innings.

"I'm not a strikeout pitcher, I'm a ground ball pitcher. I know my role," Frias said last month. "You have to get a ground ball. You never see a ground ball hit over the fence."

Frias will wear the same No. 77 he wore as a non-roster invitee during spring training.

Perez is 0-3 with a 5.03 ERA this season, with 30 strikeouts and 21 walks in 39⅓ innings. Since the All-Star break he has allowed five runs in 5⅔ innings with six walks and two strikeouts. He had an MRI exam on his right ankle after Sunday's game.

"It's been something that's been bothering him for a week, and he had more soreness after the game," Mattingly said.

To make room on the 40-man roster for Frias, the Dodgers transferred Paul Maholm from the 15-day to the 60-day disabled list. Maholm is out for the season with a torn ACL in his right knee.