Just days after Rafael Nadal suffered an agonizing and rare defeat against Taylor Fritz in the Indian Wells final, the 21-time Grand Slam champion from Spain announced that he was diagnosed with a stress fracture in his rib cage and would be sidelined for up to six weeks. 

"This is not good news, and I did not expect this," Nadal tweeted on Tuesday. "I am down and sad because after the start of the season I have had such a good time. I reached a very important part of the year with very good feelings and good results.  

"But I've always had that fighting and overcoming spirit and what I will do is be patient and work hard after my recovery. Once again I thank everyone for the support."  

Nadal's illustrious career has been plagued by injuries. He missed most of the second half of last season due to a chronic foot condition after losing to Novak Djokovic in the semifinals of the French Open.  

But a rib fracture can be slow to heal and the latest setback represented a serious blow for the 35-year-old veteran, who enjoyed his best start to a season.  

He has already pocketed three titles this campaign, including his record 21st Grand Slam trophy at the Australian Open. He had won 20 consecutive matches before losing to Fritz. On Monday, he returned to world number 3 in the ATP Tour Rankings.

However, the writing was on the wall when Nadal told reporters after the Indian Wells final that he had breathing difficulties during his encounter with Fritz. He made 34 unforced errors in the match compared to 22 from his American rival. 

"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," said the Spanish superstar. "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." 

Nadal's injury would force him to miss the Monte Carlo Masters, which runs from April 10 to 17 and the Barcelona Open which starts on April 16. And it could be a race against the clock for him to compete in the Madrid Open in early May.

Nadal will have to rediscover his best form as soon as possible after a long lay-off with injury if he manages to return for the French Open that begins on May 22.  

Thirteen of Nadal's record 21 major titles have come at Roland Garros, but for the resilient Spaniard, reclaiming his most familiar trophy could be another uphill battle.