Tim Duncan has never lost a first-round playoff series, and only once since the Spurs won their first championship in 1999 has San Antonio not advanced in the postseason. But down 3-1 to the Dallas Mavericks, the third-seeded Spurs must win at home Tuesday night in Game 5 or their season is done.

"We haven't been in that position very often," Popovich said Monday. "It is what it is. You just play the games and deal with it."

It was a typical, non-alarmist Popovich response. But it's been anything but a typical postseason for the Spurs, who are saddled with trying to become just the ninth team in NBA history to storm back from a 3-1 deficit and win a series.

Unmoved by the daunting task facing San Antonio are the Mavericks, who want to seal their first playoff series victory in three years and not be lulled into a Game 6 back in Dallas.

"We should know the importance of closing a team out when you get the chance," Mavs forward Dirk Nowitizki said. "But they're a great team with a lot of pride that plays well at home."

The Mavs have been here before: Up 3-1 against the Spurs in the 2006 conference semifinals, San Antonio rallied to even the series and forced Dallas to wrest the series in overtime of Game 7.

"I've never lost in the first round," Spurs guard Tony Parker said. "It's just a different situation. Right now, Dallas is just playing better than us. We've been down 3-1 before, and we came back and gave us a chance in Game 7. So that's the motivation right now, to take care of Game 5."

The Spurs haven't been ousted in the first round since 2000, when Phoenix booted San Antonio in four games while Duncan sat on the bench with torn cartilage in his knee. Since then, San Antonio has been pushed to the brink in the first round only once, beating Seattle in a decisive Game 5 in 2002.

"We've put ourselves in this hole," Duncan said. "We're either going to step up and win this game or we're going to go home. We face reality."

San Antonio knows the drill: Stage a miraculous comeback, and it's the Spurs' smart and tested playoff veterans who put them among the few NBA teams who can out of such a big hole. Lose, and they're an aging and fading NBA power whose better days are behind them.

After losing in five games to the Lakers in the Western Conference finals last season, Popovich bristled at the suggestion that age always doomed the Spurs. He could say the same in this series, since the Spurs appear more in need of better shooters than younger legs against Dallas.

Role players, always essential to San Antonio, have fizzled this series. Duncan and Parker combined for 75 percent of San Antonio's points in a 99-90 loss in Game 4, and it still wasn't enough. The duo made 25 of 42 from the field, and everyone else had 6 of 28.

It appeared to underscore how much the Spurs are missing Manu Ginobili, who is out for the playoffs with a stress fracture in his ankle. The Mavericks have taken notice, too, that his absence alone makes this hardly the same Spurs who stormed through the playoffs in previous seasons.

"They're missing a big part of what has been the nucleus of their team" Mavericks guard Jason Terry said. "Manu Ginobili is 35-40 percent of their offense. When you're missing that, it's a big hole."

Duncan, however, said Ginobili's absence is no excuse for the unfamiliar position the Spurs find themselves.

"Being down 3-1, we didn't expect to be here," Duncan said. "Losing Manu ... obviously takes a lot from our team. We came into this series not saying 'poor us' or whatever, we came into this series thinking we have a chance and we can win it.

"We're still of that mindset. We'll see what happens."