WASHINGTON -- As the playoff race heats up, teams fight to keep injuries from spoiling their season.

The Mets are no different, as several key players have their status decided on a day-to-day basis. Manager Willie Randolph is trying to keep the remaining players fresh while biding his time with several starters.

First baseman Carlos Delgado was kept out of the lineup after reporting no improvement on his left knee, which he hyperextended on Wednesday night.

Delgado received treatment Friday, and took some swings in the indoor batting cage at RFK Stadium, but did not take the field during batting practice.

"I just don't want to drag this out any longer than I have to," he said. "I don't want to be playing one day and miss two days. If that's the case, I'd rather miss two days now and be ready to play the rest of the year."

Randolph said that Delgado would be available to pinch-hit Friday if it was absolutely necessary.

Catcher Ramon Castro's condition worsened on Friday, and he said that if he was not feeling better on Saturday, he may have to go on the disabled list.

Castro has been battling back pain, and he said that he couldn't run while attempting to do some exercises on Friday.

If Castro does go on the disabled list, the club can make it retroactive to Aug. 12, the date of the last game he played, which means he could return before the end of the month.

"Hopefully just nine days, get better and come back," he said.

Randolph said that he was not going to rush the catcher back prematurely from what could be a serious injury.

"With a back injury, that's obviously a big part of what catchers do, getting up and down," he said.

Mike DiFelice started in Castro's place on Friday.

Right fielder Lastings Milledge also remained out of the lineup, with Shawn Green filling in. Milledge missed Thursday's game with flu-like symptoms, which persisted on Friday.

"He says he feels better, but not quite yet," Randolph said. "He's still a little weak and tired, so we'll give him another day."

Manny's magic: The Nationals were predicted to lose more games than any other team in baseball at the beginning of the season, but nobody's saying that anymore. Now the popular prediction is that manager Manny Acta will be named National League Manager of the Year.

Acta is in his first season with the team, after serving as the Mets' third-base coach in 2006.

"I just wanted a chance to show people that I could manage in the big leagues," he said. "It's been tough because of everything we had to go through and the predictions that were made against our club. But that's never been the goal here. The goal was not to win 41 games and start celebrating."

Washington was 55-66 entering Friday's game, and one game behind fourth-place Florida in the division. Acta was asked to handicap the playoff race, and stood by his old team.

"I'd like to be in the Mets' position, three games up with all that talent," he said. "It's going to be interesting. I still think the Mets are the team to beat."

Pedro's recovery: Right-hander Pedro Martinez will take the mound Monday night in Florida for a rehab start with the Port St. Lucie Mets.

It will be his third rehab start as he continues recovering from rotator cuff surgery he had in October 2006.

On the lighter side: Reliever Billy Wagner has finished reading "Harry Potter and the Deathly Hallows." He said he enjoyed the ending, but that it would look even better when it was filmed as a movie.

Chavez starts in Florida: Outfielder Endy Chavez, on the disabled list with a strained left hamstring, started in St. Lucie, Fla., on Friday afternoon.

He played the entire seven-inning game in left field, going 1-for-3 with an RBI double.

Coming up: The Mets remain in Washington for Game 2 of the intradivision series. Left-handers Oliver Perez (10-8, 3.46) and John Lannan (1-1, 3.00) will take the mound. First pitch is scheduled for 7:05 p.m. ET.