Alcaraz praises Sinner's level but also warns the Italian that he will 'have a big target on his back' at the US Open.

Spain’s Carlos Alcaraz has issued a big warning to his rival Jannik Sinner ahead of the U.S. Open. The fourth and final Grand Slam of the year will get underway on Sunday, where Sinner and Alcaraz will be the top two seeds in the men’s singles category.

They'll still play the full U.S. Open starting Sunday in New York, but it might save some time to skip ahead to the men's final on Sept. 7.