Cards ace goes on DL

PITTSBURGH -- Cardinals staff ace Chris Carpenter was placed on the 15-day disabled list Monday after an MRI exam in St. Louis revealed arthritis and a previously undiscovered impingement in his right elbow.

Carpenter, limited to one start this season, will rest for the next 10 days to two weeks and will be re-examined after that. The condition sometimes requires surgery but also can be cured by rest and treatment.

According to a statement issued by the team, there was no evidence of an acute ligament injury -- a problem that would have required surgery and likely would have finished Carpenter's season.

An impingement occurs when a thin layer of membrane that lines the elbow becomes caught in the elbow joint. The problem is relatively common among athletes who have a repetitive elbow motion, such as throwing a pitch or swinging a golf club. Arthroscopic surgery can repair the usually painful injury if initial treatment is not successful.

Carpenter, the NL Cy Young Award winner with a 21-5 record in 2005, hasn't pitched since allowing five runs in six innings during a 6-1 loss to the New York Mets in the majors' season-opener April 1. He also was scratched from a scheduled start Friday against Houston.

Cardinals catcher Yadier Molina wore a ski mask under his helmet during the first inning of Monday's game against the Pirates in Pittsburgh. The temperature at the start of the game was 37 degrees.GENE J. PUSKAR Associated Press

Carpenter flew with the Cardinals from Houston to Pittsburgh after Sunday's game, but stayed on the chartered plane because it was returning to St. Louis. With Carpenter unable to make his previously scheduled start tonight in Pittsburgh, left-hander Randy Keisler was called up from Class AAA Memphis to pitch.

The 30-year-old Keisler signed with St. Louis during the offseason as a free agent. He had no decisions and a 4.50 ERA in 11 games last season with the Oakland Athletics. He is 4-4 with a 6.82 ERA in 51 games over five major league seasons.

"It was his day to pitch. He's got some experience," Cardinals manager Tony La Russa said.

Keisler gave up one run and five hits in five innings in his only start this season for Memphis. He was effective during spring training for St. Louis, allowing only an unearned run and three hits over eight innings in four games.

La Russa said it will be difficult for the Cardinals to replace Carpenter, who has won 51 games the last three seasons. St. Louis also lost Jeff Suppan, Jeff Weaver and Jason Marquis to free agency.

"Our strength is sending a guy out there every day who has a chance to win," La Russa said. "We're not going to make up for Carpenter missing unless Keisler gives us a chance."

Carpenter, who turns 32 on April 27, initially complained of soreness a day after opposing the Mets. He was examined by the team's medical staff on April 2 but did not undergo an MRI that day. Carpenter said the elbow didn't bother him during the Mets game, but he began experiencing swelling afterward.

Carpenter was an All-Star in each of the last two seasons, going 15-8 last season, and is the only remaining starter from St. Louis' season-opening rotation a year ago. He has a 100-69 career record with the Toronto Blue Jays and Cardinals.