OKLAHOMA CITY (AP) Father Time can be awfully sneaky.
San Antonio forward Tim Duncan turned 40 last month, and the basketball world marveled at his accomplishments. Sure, his minutes were scaled back this season, but he played a significant role in helping the Spurs have their best regular season ever.
Suddenly, though, Duncan looks his age.
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He has struggled in the past two games of the Western Conference semifinals against Oklahoma City's young front line featuring Steven Adams and Enes Kanter. In Game 3, the 15-time All-Star, five-time NBA champion and three-time Finals MVP went scoreless in 12 minutes, committed four fouls in the first half and did not play in the fourth quarter. In Game 4, Duncan was 1 for 6 from the field and scored five points in 28 minutes.
Duncan likely will need to play more like his former self if the Spurs are to extend their season, and perhaps his career. Duncan has a player option for next season, and he hasn't made it clear what he will do.
When asked what he was doing to be effective against Duncan, Adams said ''Nothing,'' perhaps not wanting to give the future Hall of Famer any additional motivation.
Adams and Kanter also have slowed LaMarcus Aldridge, who averaged 39.5 points on 75 percent shooting the first two games. That has dropped to 21.3 points per contest on 36.7 percent shooting the last three games.
''He had a lot of open looks,'' Kawhi Leonard said of Aldridge after Game 5. ''They just didn't fall. It's basketball. Once we play the right way and get the shots we take and play hard, that's all we could do.''
Adams, a 7-foot center from New Zealand, is averaging 10.2 points and 12.0 rebounds in the series. Kanter, a 6-foot-11 forward from Turkey, is averaging 9.0 points and 7.6 rebounds. They usually don't play together, but have been both been on the floor late in the past two games. Thunder coach Billy Donovan said Kanter and Adams have put in the time to make the experiment successful.
''I give them a lot of credit because, although we did it a little bit during the regular season, being able to get with those guys after practice and talk with those guys, seeing them work together to try to play off of each other - they've had to space the floor and work together.'' Donovan said. ''They've got a good bond going there.''
A look at Thursday's night's Game 6.
Spurs at Thunder, Oklahoma City leads 3-2, 8:30 p.m. ET., ESPN
In Game 4, Kevin Durant went off. In Game 5, it was Russell Westbrook's turn.
If either - or both - get going in Game 6, the Spurs could be done for the year.
Both have struggled at times with their shots during playoffs, but there are signs that could be changing. In Game 4, Durant scored 29 of his 41 points in the second half. In Game 5, Westbrook made 12 of 27 shots and scored 35 points.
The Thunder want to bring their best effort in Game 6 because they're really not interested in going back to San Antonio for Game 7.
''Closeout games are the hardest,'' Durant said. ''We know they're going to try to force this Game 7. We can't rely too much on our crowd. We can't be relaxed knowing that we're going to be at home. And they beat us at home in Game 3.''
Even if Westbrook misses shots, the Thunder aren't concerned.
''Who cares about shooting percentage,'' Durant said earlier in the week. ''Obviously, we want him to - in a perfect world, we'd want him to shoot 65, 70 percent. But he's getting good shots. It's not like he's getting terrible shots. He's getting good looks. He's getting to the rim. It's just a matter of the ball going in and out of the basket.''
Westbrook is a major reason the Thunder are hurting the Spurs on the glass. Oklahoma City out rebounded San Antonio by an average of seven rebounds over the first five games, and has won that battle in each of the past four games. The Spurs feel they need to do better in Game 6 to have a chance.
''Control the boards,'' Spurs guard Tony Parker said. ''That's the key of the series. We have to control the boards. We can't keep giving them opportunities to score.''
Follow Cliff Brunt on Twitter: www.twitter.com/CliffBruntAP .
Freelancer Raul Dominguez in San Antonio contributed to this report.