The Spurs have a reputation in the NBA for front-office smarts, but this decision hardly required brainpower: give Duncan a longer rest, and maybe they would get a few more good weeks out of him.
But on the cusp of May, who saw this roaring playoff start against Dallas coming?
"It was like the old days when you give him the ball and it's automatic," Spurs guard Tony Parker said.
After laboring in the final weeks of the regular season, Duncan is averaging 26 points and 12.5 rebounds against the Mavericks, who head to San Antonio on Friday with the series tied at one game apiece.
Duncan perhaps saved the Spurs from coming home in a 2-0 hole. As the Mavs threatened to erase a 20-point deficit Wednesday night, the Spurs went to their franchise cornerstone on four straight possessions in the fourth quarter. Duncan delivered each time.
Hardly anything new -- but hardly anything the Spurs have seen recently. Crunch-time baskets over the last month had been the job of Manu Ginobili, whose resurgence since the All-Star break salvaged a Duncan-era worst No. 7 playoff seed for San Antonio.
Duncan, meanwhile, averaged 15.5 points down the stretch. He looked tired and rigid in his movement. As recently as late March he limped out of the locker room favoring his balky left knee, which has been guarded with a brace all season.
"For two or three weeks there toward the end of the season, I was starting to wear down a little bit," Duncan said after scoring 25 points and grabbing 17 rebounds in Game 2.
But maybe this was the Spurs showing their wisdom again, knowing what others might have forgotten: that Duncan was saving his best for a championship run.
"He's always that guy that gets taken for granted because he's been doing that for so many years," Spurs coach Gregg Popovich said. "Just being an anchor for us."
The Mavs know that well. Starting with a thrilling seven-game series in 2006 and including last season, Dallas and San Antonio have met in 13 playoff games. Duncan has led the Spurs in scoring in nine of those meetings, at an impressive average of 31.1 points in those games.
Games 1 and 2 were Duncan's first back-to-back games of 25 points or more since December.
"There's a reason why he's the best power forward to ever play this game," Mavericks center Brendan Haywood said. "When you play your best defense and it looks like he has nowhere to go, he still finds a way to score."
But ultimately, the Spurs haven't beat Dallas in a playoff series since 2003. And the Spurs stealing home court advantage Wednesday night probably doesn't mean much against the NBA's best road team.
The Mavs were just one game better at home (28-13) than they were on the road (27-14) this season.
"The good thing is we won big road games all season long," Mavericks forward Dirk Nowitzki said. "We're a good road team, and we have to get a big one Friday."
Duncan's contract is up in 2012, and he said during the All-Star break that he would only extend his career longer if his body will let him.
Duncan chartered career lows in virtually every category this season, including minutes (31.3 per game). Besides playing less and starting his training regiment a month later this season, he also shed 15 pounds.
All to extend his season as long as possible. It's working so far.
"If he's out there on one leg in a wheelchair," Spurs guard Richard Jefferson said, "we're going to get him the ball."