Rafael Nadal announced Tuesday that he'll be sidelined four to six weeks with a stress fracture in his left rib.
Nadal, winner of 21 Grand Slam singles titles, complained of an ailing chest following Saturday's semifinal victory against Spanish compatriot Carlos Alcaraz at the BNP Paribas Open in Indian Wells, Calif. Taylor Fritz posted a 6-3, 7-5 win over Nadal in the final on Sunday.
Nadal took to Twitter on Tuesday to address his health to his fans.
"This is not good news and I didn't expect it," Nadal wrote in Spanish on Tuesday. "I'm devastated and sad because it comes after a great start to the season. I was coming to a very important part of the year with very good feelings and good results.
"I have always had that spirit of fighting and ... I will ... work hard (for) my recovery."
Nadal, 35, won his record-setting 21st Grand Slam title at the Australian Open in January. He improved to 20-0 this season before Sunday's loss.
Nadal was laboring during the match and took two medical timeouts -- one following the first set and the other while trailing 5-4 in the second.
"I had pain, honestly. I had problems breathing. I don't know if it's something on the rib, I don't know yet. When I'm breathing, when I'm moving it's like a needle all the time inside here. I get dizzy a little bit because it's painful," Nadal said on Sunday. "It's a kind of pain that limits me a lot. It's not only about pain. I don't feel very well because (it) affects my breathing.
"(It is) more than (being) sad for the loss, (that is) something that I accepted immediately, and even before the match ended. It's more about that I am suffering a little bit, honestly."
Nadal has won a record 13 titles at the French Open. This year's event is scheduled to start on May 22.