HOUSTON -- The Cardinals expressed optimism on Thursday after Jason Isringhausen underwent surgery on his problematic left hip. Nonetheless, Isringhausen's availability for the beginning of the 2007 season is in doubt.

Isringhausen had an operation to debride, or clean up, arthritis in his hip as well as to ease an impingement. The second procedure was the more involved, as Dr. J. Thomas Byrd of Nashville, Tenn., performed a "mild re-contouring" of the femoral neck of the joint. The femoral neck is located below the femoral head, which is essentially the ball in the ball-and-socket joint of the hip.

"No timetable is set now for a return to competitive baseball," said head athletic trainer Barry Weinberg. "He's going to be out for a month. He'll have no impact activities for up to three months."

Isringhausen remained in Nashville on Thursday. He will return to St. Louis over the weekend and is expected to join his teammates at Busch Stadium on Monday for the beginning of the team's final 2006 regular-season homestand.

Weinberg said that in a best-case scenario, Isringhausen will be available to do some throwing at the start of Spring Training, but even then, the right-hander would be limited.

"Hypothetically speaking, if things go as planned, he will come to Spring Training probably with a modified throwing program," Weinberg said. "He won't be able to start Spring Training with no limitations."

Following the 2004 season, Isringhausen underwent surgery to repair the labrum of his left hip. According to Weinberg, that repair looked good when Byrd performed Thursday's procedure.

Eckstein very close: A workout Wednesday left David Eckstein in a fine frame of mind Thursday. Eckstein hasn't started a game since he suffered a strained left oblique muscle on Aug. 18, but it doesn't seem to be out of the question that he could be in the lineup this weekend in Houston. The shortstop is now able to make all of his regular throws and pivot on a double play without pain.

"I had a very good day yesterday, for the first time," Eckstein said Thursday. "And so we wanted to go and repeat it today.

"It's very positive. I'm very optimistic."

Weinberg is essentially putting the decision in Eckstein's hands at this point.

"It's just input from him," Weinberg said. "He's at the stage where, if he feels comfortable in all his movements out there, [he can play]. Final approval comes from him, not from me. Put it that way."

New affiliate: The Cardinals will have their third different short-season Class A affiliate in three years for 2007. After one year in State College, Pa., that team has affiliated itself with the Pittsburgh Pirates. As a result, the Cardinals are looking again. They will likely remain in the New York-Penn League. The Cardinals' affiliate in the NYPL prior to 2006 was New Jersey.

Bits and pieces: The Cardinals started a lineup featuring all right-handed hitters or switch-hitters against Houston lefty Andy Pettitte on Thursday. ... Entering Thursday, the Cardinals are 12-21 on the road since the All-Star break and have lost four straight road series. Yet at home, they're 46-27, 20-10 since the break and have won seven straight series.

This date in Cardinals history: On Sept. 21, 2001, Albert Pujols hit a game-winning -- though not game-ending -- grand slam as the Cardinals beat the Pirates, 9-5, at PNC Park. With a tie score going into the ninth, the Cards loaded the bases on two singles and a walk. Pujols delivered the win with a circuit clout off Omar Olivares, and Gene Stechschulte closed it out.

Coming up: Game 2 of this four-game weekend series is set for Friday night. Jason Marquis will look to even his record at 15-15 when he goes against rookie Jason Hirsh. The start time at Minute Maid Park is an unusual 6:05 p.m. CT for an ESPN broadcast.