HOUSTON -- Chris Duncan and his Cardinals teammates were still awaiting the exact results from tests on Duncan's knee as of Friday evening, but optimism is growing. Duncan's father, pitching coach Dave Duncan, said that he hopes his son could be out of the hospital as early as Saturday.

"He doesn't have a fever," Dave Duncan said on Friday. "He had a fever yesterday. So the infection has been getting out of there. They've got him on intravenous antibiotics. The cultures come back tomorrow morning, and they're hoping to let him out of the hospital tomorrow."

Chris Duncan is recuperating from an infection and bursitis in his left knee. According to the Cardinals, the infection is not a staph infection, which would lead to much greater worry about his ability to come back.

The club will not make a roster move with Duncan until at least Tuesday. If at that point he still is not close to returning, then he might be placed on the disabled list. In the meantime, the Cardinals are hoping to avoid deactivating the slugging outfielder.

"I just don't think we should lose Chris Duncan for a week if he's ready to go Tuesday," said manager Tony La Russa. "That's what I think it comes down to. I think he's important enough that we wait till Tuesday. I'd hate for him to be ready Tuesday and us put him on the disabled list."

Eckstein returns: David Eckstein returned to the lineup on Friday night, his first start in six days. Eckstein had been sidelined due to soreness in the middle of his back. He went through full workouts on Wednesday and Thursday in Colorado, and was cleared to play for the opener of the Houston series.

"He says he's ready to go," La Russa said. "He's going to work out. He knows what's at stake. He knows how he feels."

Eckstein had been streaking before sustaining the injury. He was 9-for-22 in his previous five games and 17-for-40 over the 10 games before he was shelved.

Reyes gets the ball: Anthony Reyes made his 2007 Triple-A debut on Friday night. After struggling with the Cardinals, Reyes was optioned to Memphis to work on his game. Dave Duncan emphasized that minimizing damage -- largely by keeping the ball down with runners on base -- is a key for Reyes.

"He's got to understand what he needs to do at this level in order to stop things happening when they start happening," Duncan said. "Guys start getting on base against him, and instead of giving up three or four runs, he's got to learn what he has to do to maybe give up one."

Duncan acknowledged that the situation might be different if Reyes had received more run support and had two or three wins. Nonetheless, both Duncan and La Russa feel strongly that the right-hander has plenty to work on.

This date in Cardinals history: On June 1, 1996, Tom Pagnozzi hit a solo, walk-off home run off Xavier Hernandez in the 10th inning, giving the Cardinals a 5-4 win over the Astros at Busch Stadium. The victory pulled the Cards to within one game of the first-place Astros. Thanks to Project Retrosheet for the information.

Baby 'Birds: Rick Ankiel hit a walk-off home run for Triple-A Memphis on Thursday, giving the Redbirds a 6-5 win over Tucson. Edgar Gonzalez hit a solo shot in the eighth to tie the game, setting up Ankiel, and starting pitcher Mike Parisi also went deep. ... Double-A Springfield was off. ... Class A Palm Beach allowed five runs in the eighth to lose to Jupiter, 10-9. Allen Craig had a big day, doubling three times and scoring twice. Craig, a 2006 draftee out of UC Berkeley, is having a huge year in his debut at full-season ball -- putting up a .318/.356/.544 line in a notoriously tough league for hitters. ... Brandon Buckman hit his 11th home run, Christian Reyes went deep twice and Daryl Jones hit a pinch-homer in Class A Quad Cities' 9-6 win over Clinton.

Parisi gets the call as player of the day, for turning in a fine performance after a rough first inning. He allowed three runs in the first, and then no more over his next five frames, finishing with a quality start -- plus he went 2-for-2 with that homer and a single.

Coming up: Kip Wells will try to rekindle the hometown magic when he tries for his third win of the season on Saturday afternoon. Wells pitched an outstanding game against the Astros earlier this year. He'll go against Chris Sampson, with first pitch set for 2:55 p.m. CT.