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The New York Knicks believe Amare Stoudemire will be available Friday for Game 3 of their playoff series, but sound less hopeful that Chauncey Billups can play.

Stoudemire took part in the Knicks' morning shootaround Friday and was getting more treatment on his back. He missed the second half of Boston's Game 2 victory because of back spasms.

Stoudemire said after the game it was the first time he had experienced that injury, and his ability to deal with the pain could determine how effective he will be if he does play.

"I think right now a lot of it is psychological in the sense of can he trust his back and can he get out there and just not worry about it, and every individual responds a little bit differently," Knicks coach Mike D'Antoni said. "But he's a warrior and I don't doubt him for a second."

D'Antoni said he was "pretty optimistic" about Stoudemire but "less optimistic" about Billups, who strained his left knee late in Game 1 and could miss his second straight game. The point guard received treatment Friday but did not practice.

Toney Douglas would start in Billups' place, but the Knicks don't have a good option to replace Stoudemire, who had 28 points and 11 rebounds in the series opener. Yet D'Antoni said he would not leave his All-Star forward on the floor if he can't perform.

"That's the tricky part of it, because we're going to win on grit and hustle and toughness," D'Antoni said. "If he can go and feels good, great. If he's down, then we'll have to make a decision during the game. That'll be something you have to watch and feel."

The Celtics bring a 2-0 lead into the first postseason game at Madison Square Garden in seven years.

Carmelo Anthony nearly led the short-handed Knicks to a victory in Game 2 with 42 points and 17 rebounds. He said the Knicks need to play the same way they did in Boston no matter who's out there with him.

"It's a tough situation because at playoff time right now you want to be full strength," Anthony said. "But you've got to go out there and just play now, regardless if they're there or not. Guys have got to step up, guys got to come out and match the intensity that we had in the first two games."