Third base is an interesting place for the Phillies these days.

For more than a month, Kevin Frandsen held down the position remarkably well, hitting .331 with a .380 on-base percentage while doing a respectable job defensively.

And then last week an MRI examination revealed a stress fracture in his left fibula. He has made just one pinch-hitting appearance since, and general manager Ruben Amaro Jr. said Tuesday that it's unlikely Frandsen will be able to return to his role as the regular third baseman.

"He's not going to be our regular third baseman," Amaro said. "I don't think he can do it physically. I don't want to have a guy playing on a broken ankle. Even though it is just a stress fracture, we're not going to put him out there and have him try to do something he can't do.

"So he might play one day, then get another day off. He might come in for an emergency situation or he may come in to pinch-hit. It depends on how he feels."

Frandsen said he feels better than he did a week ago in Cincinnati, when he was first sidelined by the injury, and he remains determined to get back on the field.

"I feel like that, yeah," he said. "But it's their decision, not mine. That's how I have always been. My play and the way I look out there says everything and speaks for itself. Whether it's not good or good. I'm not here to try to trick anyone, especially in this situation. I'm gearing up to play, though. I feel like I can play."

Not playing, however, has bothered Frandsen.

"It stinks," he said. "It stinks."

With Frandsen down and Placido Polanco out of sight and out for the season, the job of playing third base has belonged to Michael Martinez. He made his sixth straight start at third and had hit .313 in the five previous games.

"He can catch the ball," manager Charlie Manuel said. "He can catch it and throw it and he's starting to get on some. He did a good job running the bases" Monday night.

Now that the Phillies have willed themselves into the race for the second wild card, they have to decide if they want to play their wild card at third base.

That wild card would be Chase Utley, who started taking ground balls at third last month and has continued to do so. When Utley first started his third-base experiment, Frandsen was healthy and the Phillies were so far removed from any sort of race that it was all being done with an eye toward next season.

Could that move to third happen sooner than anticipated?

"I don't know," Amaro said. "He's only been out there two or three times now, but I think they're going to continue to work on it. Really, it's up to Chase in a lot of ways and I guess it's up to us to evaluate whether he can truly do it."

Just to make things a little more interesting at third base, catcher Carlos Ruiz still takes ground balls at the position occasionally, too.

Ruiz starts

Ruiz started his first game behind the plate since Aug. 2, which was the day before he went on the disabled list with a foot injury. Ruiz had made an appearance Sunday in the second game of the doubleheader with Colorado when he pinch-hit and remained in the game as a defensive replacement.

Amaro and Manuel said Erik Kratz would continue to get most of the catching work.

Ruf still waiting

Juan Pierre started in left field Tuesday night, which meant Darin Ruf was still waiting for his first major-league start. "Whatever experience he gets here is great," Amaro said. ". . . I'd like to see him out there on the field and I'd like to see him get an opportunity, but we're trying to win as many games as we can, so Charlie is going to play the best lineup he can."