At his best, Rajon Rondo can seize a rebound, dart away from defenders, and set himself or an All-Star teammate up for a basket.

Amare Stoudemire can shake a backboard with a powerful dunk, or scare a spectator sitting courtside by forcefully blocking a shot out of bounds.

He can't right now, though.

Rondo is rolling and Stoudemire is sore, a big reason the Boston Celtics will bring a 3-0 lead over the New York Knicks into Game 4 of their first-round series on Sunday.

The Celtics will be looking for their first sweep since beating Indiana in three games in 1992, so long ago that it was Larry Bird's last playoff series victory.

After needing seven games just to get out of the first round in both 2008 and '09, they would welcome the chance to do something easily for a change — especially with likely second-round opponent Miami poised to finish a sweep of its series with Philadelphia.

"I've never been part of a sweep, but I don't like to think about that stuff. We don't worry about that stuff," forward Paul Pierce said after practicing at Madison Square Garden. "It's about getting better one game at a time. We want to close the series, but they're not going to give it to us."

Rondo controlled the last two games, first with a surprising scoring outburst, then with a Celtics playoff-record 20 assists Friday in his sixth postseason triple-double. He is averaging 18.3 points, 12 assists and 8.0 rebounds, the type of all-around play that led Boston to the NBA finals last season.

"He seems always to be at his top level. I'm not surprised by what he does. I think the big thing as far as Rondo that I was shocked about when I arrived to Boston was his knowledge of the game, being so young," center Jermaine O'Neal said. "A lot of that comes through his experience of playing, but he has the ability to take over a game without scoring a lot of points. His ability to direct the offense, direct defense, get guys involved, it's one of the best in the league, if not the best in the league."

Meanwhile, Stoudemire had trouble just moving around, and with his aching back feeling worse Saturday, he said he won't play Sunday unless he feels better, adding he was below 50 percent in Friday's 113-96 loss.

"It's tough, I mean it really is. My game is very explosive. I love contact, I love to get to the basket, I love to draw fouls, I love to dunk ... that's my style of play. And so with a bad back, it's kind of tough to play that way," Stoudemire said. "There are adjustments to be made in order to be effective, but again, I don't want to get out there and further injure my injury, and so it all depends on how I feel tomorrow and see if I can go."

The Knicks will probably be without point guard Chauncey Billups, who missed the last two games after straining his left knee on a drive to the basket in the closing seconds of the opener.

New York nearly won that game and Stoudemire said he felt confident after scoring 28 points that the Knicks could win the series. Then he hurt his back dunking during warmups before Game 2, leaving Carmelo Anthony as the only healthy Knicks star, and that's not nearly enough against a Boston team with four All-Stars in its starting lineup.

Though he said "life ain't fair," Anthony repeated that the Knicks can't use injuries as an excuse.

"We've got to do what we've got to do. The Xs and Os go out the window, and we've just got to play basketball," Anthony said. "We've got to fight. It's a war, it's a battle and the most important thing is just how much pride we got. I don't want to get swept, we don't want to get swept, but we've got to go out there and just leave it all out there on the court and see what happens."

Rondo missed a triple-double by one point and one rebound in the opener, then scored a playoff career-high 30 points in Game 2 before finishing with 15 points and 11 rebounds Friday.

Knicks coach Mike D'Antoni, while saying Rondo is a good player, said the high assist total comes from Ray Allen and Pierce making so many shots. Allen did the majority of his damage against rookie Landry Fields, the second-round pick who was a reliable starter during the regular season but has been overmatched against the league's career leader in 3-point shots.

Fields is averaging just two points on 25 percent shooting, but D'Antoni said he would remain in the lineup Sunday after saying Friday he would look at whether a change was necessary.

Pierce is averaging 25.3 points, Allen adding 24.7 and making 15 of 20 3-point attempts. The Celtics still won't have Shaquille O'Neal on Sunday, but have little to fear since no NBA team has blown a 3-0 deficit.

The Knicks are just trying to win a playoff game for the first time in a decade, not thinking about winning four straight against the defending conference champions.

"It doesn't matter what the situation is," D'Antoni said. "We've got to play with more energy, more urgency, and get it done. And we can do this. We can beat these guys and we've got to believe that and just try to do it Sunday."