Defending champion Carlos Alcaraz has withdrawn from this month's Cincinnati Open due to an ongoing wrist injury, tournament organisers said on Tuesday.
The 23-year-old Spaniard had been set to return at the ATP Masters 1000 event after being sidelined since withdrawing from the Barcelona Open in April.
Alcaraz was unable to defend his French Open title and also missed Wimbledon as he recovered from the injury.
"We know Carlos is doing everything he can to get back to playing tournaments as soon as possible," tournament director Bob Moran said in a statement.
World number three Alcaraz won last year's Cincinnati title after world number one Jannik Sinner retired from the final.
The Cincinnati Open will be held from August 13-23.

Police looking into reports of 'missing' athletes after Glasgow Commonwealth Games
Battle lines drawn within FIFA as key figures break ranks with Infantino
Fans and former team mates say farewell to Franco Baresi
Chile's Colo-Colo sign heroic World Cup goalkeeper Vozinha
Eala dismantles Pegula to win first WTA Tour title