It was a quick turnaround for the new No. 1 of tennis. Hours after celebrating his US Open victory, Carlos Alcaraz arrived back home to try to help Spain in the Davis Cup Finals. “I’m very proud to arrive as No. 1 and do my bit for the team,” Alcaraz said on Tuesday.

“Playing the Davis Cup is always special. It’s a unique atmosphere and I’m looking forward to being with the team.” Alcaraz made it to Valencia the day before Spain was to debut against Serbia in the group stage on Wednesday. It wasn’t yet clear in which condition Alcaraz has arrived, after having played a grueling series of matches on his way to the title in New York.

“Hopefully he can recover as soon as possible,” Spain captain Sergi Bruguera said. “We don’t know yet if he will be able to play on Wednesday.” Many expected Alcaraz to skip the Davis Cup after defeating Casper Ruud in Sunday’s final, which allowed him to become the youngest man to lead the ATP computerized rankings since they began in 1973.

The 19-year-old Alcaraz said following Monday’s traditional Times Square photo shoot that he “woke up dead” after the four-set final against Ruud. “We will see how he is feeling, we will discuss it with him,” Bruguera said.

“The sooner he can play, the better.” Before the final, Alcaraz had three consecutive five-set victories, including a 5-hour, 15-minute quarterfinal match against Jannik Sinner. Bruguera said he was not surprised that Alcaraz had begun his grand slam title collection.

“We all knew it was going to happen sooner or later,” Bruguera said. But the way he won three matches in five sets is an incredible effort mentally as well as physically. “Being the youngest No. 1 in the world, there aren’t any words.”