Novak Djokovic may still be going strong at 38, holding his own against the new generation led by Carlos Alcaraz and Jannik Sinner, but even he knows he can’t play forever. As the last active member of the legendary “Big Three,” every tournament he enters feels like a reminder that tennis is inching toward the end of an era.

Novak Djokovic delivered a lesson in Grand Slam tenacity to Learner Tien in the first round of the U.S. Open on Sunday as he battled past the American teenager 6-1 7-6(3) 6-2 and launched his latest quest for a record 25th major title.

Novak Djokovic has fielded plenty of retirement questions over the last few years. Aged 38, he’s still as motivated as ever by the prospect of winning a historic 25th Major title. But it’s been two years since he even reached a final at Grand Slam level, and some are wondering what he’ll do next.