The site of countless high points for Rafael Nadal has now become the one for a pressing, unanswered question.

Nadal, the former No. 1 tennis player in the world, lost in straight sets to No. 4 seed Alexander Zverev on Monday in the French Open — where Nadal has won 14 of his 22 Grand Slam titles — for a likely Roland Garros farewell.

While Nadal responded with “don’t assume that” when asked if this would be his final French Open, the 37-year-old acknowledged the reality of his tennis career that has come into focus amid injuries and underwhelming results.

“It’s a big, big chance that it’s going to be my last Roland Garros,” Nadal told reporters before the tournament began, according to the Associated Press. “But if I have to tell you it’s 100% my last Roland Garros? Sorry, but I will not. Because I cannot predict what’s going on.”

Nadal, who now sits at No. 275 in the world tennis rankings, dropped the first two sets, 6-3 7-6 (7-5), and Zverev broke Nadal with a sharp backhand to take a 4-3 lead in the third set.

Still, Nadal had a chance to get back on serve, but couldn’t capitalize on his chance to break Zverev.

And five points later, Nadal waited for Zverev at the net, with a 6-3 third set now completed, and walked off the court for what could be the final time — with the crowd chanting his name — in the tournament that has become synonymous with his name.