CLEARWATER, Fla. — Phillies closer Brad Lidge caught a spike in the mound on his first pitch of batting practice today and hurt the same knee he had surgery on in October.

Lidge, the Phillies' biggest offseason acquisition, limped off the field after talking with team trainers. The team said it hoped to know more about the extent of the injury tomorrow.

"It was my push off leg," Lidge said. "I caught my spike in the mound. I threw the pitch but it felt like I pulled something in the knee. ... It swelled up a little, but I'm optimistic that I just pulled some scar tissue loose."

Doctors removed torn cartilage from the knee in the fall.

The Phillies acquired Lidge and infielder Eric Bruntlett in a November trade that sent speedy outfielder Michael Bourn, infield prospect Mike Costanzo and reliever Geoff Geary to the Astros.

The 30-year-old Lidge, who has 123 career saves, finished 2007 with 19 saves in 27 chances and a 3.36 ERA for Houston. When the Phillies acquired him, it allowed them to strengthen their rotation by making Brett Myers a starter again.

"We'll find out more tomorrow," manager Charlie Manuel said of Lidge's injury. "We'll go from there and we're waiting to see how it feels (Sunday). He was in the stretch and threw one pitch and did it. He threw another and it still hurt him."

The Phillies struggled with injury problems in the bullpen for much of last season. Setup man Tom Gordon and Myers both missed significant time due to injuries.