Rafael Nadal has suffered a stress fracture in his rib and will be out for up to six weeks, the Spaniard's team said on Tuesday.
Nadal, the winner of 21 Grand Slam singles titles, complained of a chest issue during his run to the final of the ATP 1000 event in Indian Wells, California last week.
Upon his arrival in Spain on Tuesday, Nadal visited his medical team in Barcelona for tests which revealed "a stress fracture of the third left costal arch".
"This is not good news and I did not expect this," Nadal said in a statement sent by his team.
"I'm disappointed and sad because after a good 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's injury occurred during his three-set semi-final victory over teenaged compatriot Carlos Alcaraz but he still played the final in which he went down to American Taylor Fritz - his first loss in the season after 20 consecutive wins.
His doctor said that the 35-year-old will be out of action for "four to six weeks", ruling him out of next month's Monte Carlo Masters and putting doubts over his participation in the ATP 1000 events in Madrid and Rome in May.
The French Open, the year's second major at Roland Garros where Nadal has won a record 13 titles, is scheduled to start from May 22.
Nadal started the 2022 season unprepared and with uncertainty looming over him due to a foot problem that forced him to miss a chunk of the 2021 season including Wimbledon, the Olympics and the U.S. Open.
After suffering a bout of COVID-19 before arriving in Melbourne in January, Nadal said he had even considered retiring when the foot problem that has troubled him throughout his career resurfaced last year.
But that did not stop the left-hander from winning three consecutive titles in 2022, including the Australian Open that helped him to increase his major haul to 21 and take sole ownership of the men's record he had previously shared with Novak Djokovic and Roger Federer.