Top tennis player Jannik Sinner left the U.S. Open on Friday.

He said he could not get better from a right knee injury in time.

The injury has kept him out since he won Wimbledon last month.

Sinner beat Alexander Zverev at Wimbledon.

It was his second straight title there.

Then he did not play in the hard-court tournaments in Montreal and Cincinnati.

The 25-year-old Italian said he will not be ready when the main draw starts on Aug. 30.

He wrote on X that he is sad and disappointed.

New York is a special place for him.

Sinner won the U.S. Open in 2024.

He lost to Carlos Alcaraz in last year's final.

Alcaraz said on Thursday he would be ready to play in New York.

He has been out since April with a right wrist injury.

The two have met in the last three Grand Slam finals in 2025.

Alcaraz won the most recent one in New York.

Sinner has a 44-3 record with six titles this year.

He had a surprising loss at the French Open.

Then he won Wimbledon for his fifth Grand Slam title.

This will be his first missed Grand Slam since his major debut at the U.S. Open in 2019.