Seven-time Grand Slam champion Carlos Alcaraz said the uncertainty over when he would return to competition was the most difficult part of a wrist injury that kept him sidelined for nearly five months ahead of his U.S. Open title defense.

The 23-year-old Spaniard, who became the youngest man to complete a career Grand Slam when he won his seventh major at this year's Australian Open, returns to Flushing Meadows with limited match practice but high expectations as he seeks a third U.S. Open title.

Alcaraz missed most of the clay-court season and was forced to sit out the French Open, Wimbledon and the North American hard-court swing because of the injury. He made his competitive return earlier this week, partnering with 23-time singles Grand Slam champion Serena Williams in mixed doubles.

"The first month was kind of difficult for me because I couldn't do anything with my right arm. It was tough," Alcaraz told reporters Friday.

"But at the same time, I enjoyed my time with family, friends and staying at home.