Grand Slam champion Novak Djokovic won't be taking part in the Cincinnati Open, meaning that he won't have any warmup matches on hard-courts before the US Open.

Djokovic, ranked No. 6 in the world, is bidding to win a record 25th major at the U.S. Open, which begins Aug. 24. He lost to world No. 1 Jannik Sinner in the semifinals at both Roland Garros and Wimbledon. The Cincinnati Open is still headlined by Sinner and Alcaraz, with many other top stars playing.