Rafael Nadal is facing renewed injury concerns after his 20-0 unbeaten run to start 2022 ended with a straight-sets defeat to 20th-ranked Taylor Fritz in the ATP Indian Wells Masters final.

The 35-year-old Spanish superstar was reluctant to discuss the upper body injury that hindered him against Fritz, insisting "it's his day," but he couldn't hide his disappointment and the worry about what it might mean for the claycourt season and his chances of a 14th French Open title.

"Honestly, I wanted to make it perfect before clay," Nadal said of a 2022 hardcourt run that saw him win an epic Australian Open final against Daniil Medvedev and lift the trophy in Acapulco.

He said the first months of the year "have been very, very, very beautiful.

"Honestly I am sad because the way I was not able to compete," he said of his inability to finish off the run with a fourth Indian Wells title.

"It is tough to have these feelings, especially every day, but in the final is very, very ugly, no?

Making things worse, the oft-injured Nadal did not yet have a diagnosis of the problem that caused him to feel pain and shortness of breath.

It began late in his semi-final victory over 18-year-old compatriot Carlos Alcaraz and he twice received treatment during his loss to Fritz.

"I had pain, honestly," Nadal said. "I have problem to breathe. 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," he said, indicating his chest.

"I get dizzy a little bit because it's painful. It's a kind of pain that limit me a lot. Is not only about pain, I don't feel very well because affects my breathing."

It's the latest in a litany of injuries for Nadal, whose Australian Open triumph was his record-setting 21st Grand Slam title.

Troubled for years with knee injuries, he saw his 2021 season cut short by foot pain that he feared could end his career.

He said his resurgence had brought him joy, and now he's focused on figuring out how to solve his latest physical problem.

"I am sad now, but I am not the kind of person that goes down or goes very high emotionally depending on the moment.

"The last months have been amazing, unforgettable, very emotional. I enjoyed things that I never thought I could live again a few months ago.

"Now it's the moment to try to solve this problem as soon as possible, try to start on clay. The thing that worries me now, it's about what's going on there, what I have to do now to recover and how long going to take."