NEW YORK -- A possibility exists that the starting lineup the Mets envisioned in December when they traded for Brian Schneider and Ryan Church may be on the field and functional by the weekend, or at least by Monday. Now that Moises Alou has been cleared to play -- though no sooner than Friday -- the only hold-up is the return of Schneider from the thumb infection that has made him unavailable since Wednesday.

An MRI, administered Monday, detected no serious damage in Alou's right ankle, the ankle that had swelled and become painful late last week during the final stages of his recovery and rehabilitation from early March surgery to repair a hernia. The Mets had announced the problem was with his left ankle, the ankle he damaged so severely in 1993, but the oft-injured, 41-year-old outfielder corrected the club's mistake Tuesday after he returned to the Mets' clubhouse.

The club remained unsure of when Schneider would be released from the Hospital for Special Surgery in Manhattan, and that is why it was vague about when Alou will be activated. Alou's return to the roster and Schneider's return to active duty are linked.

Revised information concerning Schneider also was presented Tuesday. Mets general manager Omar Minaya acknowledged Schneider does have a staph infection but emphasized it was not as serious as it might have been. He also said the thumb had been drained of pus Sunday. A player had said Monday that a procedure had been performed on the thumb Sunday. The Mets said Monday the thumb hadn't been lanced. But Minaya said Tuesday "There was no major lancing."

The thumb was cut, he said, but the incision didn't require stitches, so Schneider's recovery will not be retarded. Minaya said he was unsure whether Schneider would be immediately available to play following his release from the hospital. It is highly unlikely Schneider will play Wednesday even if he was released late Tuesday. But a return Friday, when the team begins a two-city trip to Phoenix and Los Angeles, is more likely.

If Schneider, who is not assigned to the disabled list, is ready to play Friday, the Mets will remove catcher Gustavo Molina from he big league roster and thereby create a vacancy for Alou. What the club will do to accommodate Alou if Schneider is unable to return was unclear.

Alou was delighted to be back with his teammates after spending most of the last 11 weeks in Port St. Lucie, Fla.

"I brought everything with me," he said. "I didn't want to go back. You get used to doing nothing."

He had hoped to resume playing by the end of April, but said he'd be satisfied with playing Friday. He spoke with greater certainty about a Friday return than Minaya did.

"My stamina probably isn't as good as it should be," Alou said. "I wanted to play more over the [past] weekend but I couldn't because my foot was swollen. Now, I might have to get closer going to the gym the next couple of days."

Alou said he'd like to play Friday and Saturday, and perhaps the entire weekend -- he has hit well in Chase Field in Arizona -- but he thinks he might need some time to recover, and he isn't opposed to not starting day games that are preceded by night games.

The cause of the swelling in his right foot was not determined by the MRI. But Alou reasoned that it might have been related to an old injury. He had injured ligaments in the right ankle in 2006. He said a hairline fracture might exist. The pain wasn't what prevented him from playing over the weekend, it was he swelling and the cautious approach of the club's medical personnel.

Alou played in one Class A game last week. Before that, he had played in the extended Spring Training program. He said those games might have been suitable substitutes for big league exhibition games. "They threw 95 [mph] down there," he said.