Jannik Sinner is a top tennis player.

He left the U.S. Open on Friday.

He said his right knee hurt.

He could not get better in time.

The injury kept him out.

He won Wimbledon last month.

Sinner beat Alexander Zverev at Wimbledon.

It was his second win there.

Then he did not play in Montreal and Cincinnati.

He is 25 years old and from Italy.

He said he will not be ready for the main draw.

It starts on Aug. 30.

He wrote on X that he is sad and disappointed.

New York is special for him.

Sinner won the U.S. Open in 2024.

He lost to Carlos Alcaraz in the final last year.

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

He has not played since April.

His right wrist hurt.

They met in the last three Grand Slam finals in 2025.

Alcaraz won the last one in New York.

Sinner has 44 wins and 3 losses this year.

He has six titles.

He lost at the French Open.

Then he won Wimbledon.

It was his fifth Grand Slam title.

This will be his first missed Grand Slam.

He first played a Grand Slam at the U.S. Open in 2019.