Alexander Zverev has undergone surgery on torn ligaments in his right ankle, with his brother Mischa raising major doubts that he will be ready in time for Wimbledon.
The German world No 3 was forced to retire from his French Open semi-final against Nadal last week.
Zverev fell and twisted his ankle at the end of the second set at Roland Garros, yelling in pain as Nadal rushed around the net to help.
- A year in the life of Emma Raducanu
- Nadal will play Wimbledon 'if body allows' | 'I can't keep having injections'
- Get Sky Sports | Download the Sky Sports App I News in brief
The German was helped to his feet but taken off the court in a wheelchair for treatment.
After five minutes, the 25-year-old re-emerged on crutches to inform the umpire that he could not continue.
Zverev has now confirmed he has had surgery on the injury but has not placed a time frame on his return.
Writing on Instagram, Zverev said: "We all have our own journey in life. This is part of mine. Next week I'll reach a career high ranking of number 2 in the world, but this morning I had to undergo surgery.
"After further examination in Germany, we received confirmation that all three of the lateral ligaments in my right ankle were torn.
"To return to competition as quickly as possible, to ensure all the ligaments heal properly, and to reclaim full stability in my ankle, surgery was the best choice.
"My rehab starts now and I'll do everything to come back stronger than ever!
"I am continuing to receive so many messages and would like to thank everyone once again for supporting me during such a difficult time."
- Osaka on Wimbledon entry list; Federer and Williams sisters absent
- Swiatek 'overwhelmed' by Lewandowski support & 'doing more' than Serena
Zverev's brother Mischa told German newspaper Bild that Wimbledon is "out of the question" for the 25-year-old, with the grass-court Grand Slam set to begin on June 27.
Don't forget to follow us on skysports.com/tennis, our Twitter account @skysportstennis & Sky Sports - on the go! Available to download now on - iPhone & iPad and Android