He was one of the most significant additions of the offseason, yet when the Washington Nationals took the field at RFK Stadium, Vinny Castilla wasn't in the lineup. He hasn't played since Sept. 22, shut down with tendinitis in his left knee, an ailment that hampered him all season.

And when Nationals General Manager Jim Bowden was asked if Ryan Zimmerman, the rookie third baseman who was the Nationals' top draft choice this season, is ready to be an everyday major leaguer next year, Bowden said, "He is for me -- offensively, defensively, makeup-wise."

That would appear to leave Castilla in a bit of flux. He will be 39 next July, and has $3.2 million remaining on a two-year, $6.2 million contract. Bowden -- if he keeps his job when new ownership comes on board within the next month -- likely will try to trade Castilla, a move that might require the Nationals to eat some of the money he is owed.

Castilla, though, wants to be a part of next year's team.

"I signed for two years," Castilla said. "I have to honor my contract. This has been a great experience. The second half, we collapsed, but so much good happened. Opening Day was unbelievable.

"I had a great first half. And the second half, with my knee, I couldn't use my left leg. I couldn't drive the ball. But I think if I'm healthy, I can have another good year."

Castilla finished with a .253 batting average, 12 home runs and 66 RBI -- well off his 2004 totals of .271, 35 homers and 131 RBI with Colorado. The Nationals, however, never thought he would match those marks away from Denver's thin air.

"But I thought he'd hit maybe 20 home runs," Manager Frank Robinson said.

Zimmerman finished his one-month audition with a 1-for-3 day, hitting a double, walking once and striking out twice. He is just 21, and he ended up 23 for 58 (.397) with 10 doubles and six RBI. He will take two weeks off before reporting to the Arizona Fall League.

What Next for Vidro?

Second baseman Jose Vidro won't have surgery on his ailing right knee -- for now. Vidro visited orthopedic specialist James Andrews yesterday at FedEx Field, where Andrews works as a consultant for the Redskins on game days. Andrews recommended a week of rest, and then a three-week exercise program aimed at strengthening his quadriceps muscles.

"Basically, what the doctor told me, is that my legs need to get stronger to take the pressure off my knee," Vidro said.

Vidro said he will be reexamined again after the program, and there's still a chance he would need surgery. The Nationals' team physician Bruce Thomas doesn't believe he will.

Vidro was limited to 87 games, in which he hit .275 with seven homers and 32 RBI.