The Dallas Mavericks took a knee Friday.

It's not that they've given up as they fell behind two games to one in the Western Conference finals after a 96-83 loss to the San Antonio Spurs.

It's just that a knee could mean their demise.

Mavericks star forward Dirk Nowitzki went down with a knee injury midway through the fourth quarter in Game 3 and Mavericks coach Don Nelson questioned whether Nowitzki would play again in this series.

"The news on Dirk Nowitzki is not good," Nelson said. "His knee is very sore. He twisted it somehow and it is a strain. I wouldn't expect he would play the next game. I wouldn't be sure he'll play in this series. . . . From the looks of him tonight, that's probably not going to happen."

Nowitzki went for an MRI after the game and results were to be known Saturday.

"I'll see how it feels," he said. "I can always play through some pain. [But] it doesn't make sense if I'm not 100 percent."

But if he is unable to play, it would seem difficult for the Mavericks to win another game in this series. Nowitzki came into Game 3 averaging 30.5 per game against the Spurs and 25.9 in the playoffs with 30-point games in the Mavericks' previous two Game 7 wins in these playoffs.

Mavericks backup centers Shawn Bradley and Evan Eschmeyer also are suffering from knee problems and might not be available, Nelson said.

Tim Duncan had 34 points and 24 rebounds to lead the Spurs, and Tony Parker contributed 29 points.

"We did exactly what we came here to do," said Duncan, who had 14 points in the fourth quarter as the Spurs went from leading by three to a 20-point lead with just under four minutes remaining. "We wanted to put pressure on them and want to take the next one to kind of put it out of their reach."

The Mavericks led 46-38 at halftime, holding the Spurs to 38.5 percent shooting. But San Antonio responded in the second half, blitzing Dallas with a 12-0 run to open the fourth quarter.