Carlos Alcaraz hasn't played a match in 4 months. His US Open title defense is still in doubt.
He's on the entry list. Whether he actually plays is a completely different question.
Carlos Alcaraz has been out since April with a right wrist injury, missing both Roland Garros and Wimbledon. He's still listed in the US Open entry list, but he only just withdrew from the Cincinnati Masters, a tournament that would have been his real test of match fitness before defending his title on August 30. Stephen Smith, a sports scientist who runs an injury-analytics company, said he'd be "shocked" if Alcaraz actually played.
Going from zero competitive matches in four months straight into a best-of-five-set Grand Slam is a big ask for any player, let alone one defending a title he won just a year ago against Jannik Sinner. Alcaraz is reportedly back on court and building up his training load, but there's a real difference between practicing and surviving five sets under tournament pressure. The smarter long-term move might be skipping the defense entirely, even if it means losing the title without a fight.
Watch the next week or two of practice reports closely, since that's usually where a real answer shows up before any official statement. If he pulls out, it hands the tournament to a wide-open field with no clear favorite carrying his kind of recent form.