Sonics rookie Luke Ridnour will undergo surgery today in Philadelphia to repair an abdominal injury that has bothered him for more than two months.

The procedure will take about 30 minutes, and will repair a severely strained abdominal muscle, the team announced yesterday. Ridnour will stay overnight at the hospital.

Estimates are six to eight weeks before Ridnour can practice at full speed, which is right about the time the Sonics start training camp.

Sonics general manager Rick Sund said he doesn't expect it to delay Ridnour's participation in training camp starting Oct. 1 in Seattle.

"Hopefully not," Sund said. "But you never know for sure because it depends on recovering from surgery."

Ridnour must remain largely inactive after the surgery, and it will be at least three weeks before he can begin jogging and other low-impact workouts. Ridnour suffered the injury in May at the end of a workout in Milwaukee. It was originally thought to be a strained abdominal muscle. That diagnosis was changed to an avulsion fracture after a magnetic-resonance imaging test was taken after the draft. An avulsion fracture generally is caused when a muscle contraction pulls away part of the pelvic bone.