Washington, United States (AFP) — Five-time NBA champion Tim Duncan, the San Antonio Spurs’ 40-year-old superstar big man, says he does not know if he has played the final game of his NBA career.

The future of Duncan and Argentine guard Manu Ginobili with the perennial title contenders became the key subject for the Spurs yesterday after a 113-99 play-off loss to Oklahoma City ended their season.

Duncan, who has a $6.4-million player option for next season in what would be his 20th NBA campaign, pointed to the sky as he walked off, the court following Thursday’s loss, but gave no hint of what his future might entail.

“I’ll get to that after I get out of here and figure out life. That’s it,” said Duncan, who scored 19 points and grabbed five rebounds in 34 minutes on the court Thursday.

“Tim was playing really well, so we played him as much as we possibly could because he earned the minutes,” Spurs Coach Gregg Popovich said. “He really did a good job.”

Duncan has showed he can still contribute, averaging 8.6 points, 7.3 rebounds, 2.7 assists and 1.3 blocked shots a game this season.

But the Spurs might also want to make a transition to a younger inside force to play alongside LaMarcus Aldridge and Kawhi Leonard, who have become San Antonio’s key players as the “Big Three” of Duncan, Ginobili and French guard Tony Parker have aged.

“Every year it’s the same thing with us,” Parker said. “TD, obviously, and Manu, it’s the same question every year. They’re either going to come back or not. We’ll see.”

Steven Adams, the 22-year-old New Zealand centre who worked against Duncan for Oklahoma City, was impressed with the legend, who played his first NBA game when the Kiwi was only four years old.

“It’s just amazing to see him still come out there and still be able to bust you up if he needs to,” Adams said. “It was quite awesome just playing with him. He’s [the] fountain of youth. He has found it.

“He’s still capable. He’s still in tune with their system. He could have one leg and still be able to contribute.”

Ginobili, 38, is looking at returning for a 15th NBA season and has a $2.9-million player option to do so.

“It has been an amazing run,” Ginobili said. “We all enjoy playing with each other. I’m so proud of having played with those guys for so many years and winning so many games, and even playing with the new guys.

“If there’s a reason why you always want to come back and keep being part of this, (it’s) because of the amazing chemistry, the good times and the good people that you play with and spend time with.”

Duncan, a 15-time All-Star, was voted the NBA Most Valuable Player in 2002 and 2003, and won the NBA Finals MVP award in 1999, 2003 and 2005 when he led the Spurs to titles. He was also on San Antonio championship squads in 2007 and 2014.

Duncan, Parker and Ginobili are the first set of at least three teammates to win four titles together since the 1980s Los Angeles Lakers’ combination of Magic Johnson, Kareem Abdul-Jabbar, Michael Cooper and Kurt Rambis.