MILWAUKEE -- Shortly before Tuesday's game in Milwaukee, the Cardinals announced that closer Jason Isringhausen has decided to undergo left hip arthroscopic surgery.

Isringhausen, 34, is scheduled for the operation Thursday with Dr. J. Thomas Byrd in Nashville, Tenn. The right-hander will begin physical therapy within several days, though no timetable for his return to competitive activities has been determined.

Following the World Series in 2004, Isringhausen also had surgery on his arthritic left hip, performed in mid-November and involving repair of the labrum lining the hip. He did not miss time at the start of the 2005 season as a result.

With 33 saves this season, Isringhausen (4-8, 3.55 ERA) will close 2006 with 173 for his Cardinals career, ranking as the club's all-time leader in that category. He last pitched on Sept. 6, when he suffered his career-high and league-leading 10th blown save, after recording his 249th save the previous day.