Juan Martin del Potro is unsure if he has played the last match of an injury-hit career after re-fracturing his kneecap during the Queen's Club championships.
The Argentine's injury curse struck again on Wednesday as the 2009 US Open champion slipped during his victory over Denis Shapovalov and pulled out of the grasscourt tournament.
The world No.12 will miss next month's Wimbledon, with scans revealing a fractured right patella. The same injury forced him out of the last four weeks of 2018 and restricted him to five tournaments this year.
"If that match was the last of one my career, I don't know. During rehab, I will be able to think clearly. I will know what my body is able to do," the 30-year-old said on Instagram.
Since winning the US Open, Del Potro underwent three left wrist surgeries and another to his right wrist but he fought back each time to return to the tour.
"After medical studies and talking to the doctors, they said surgery was the best treatment," he added.
"I asked them for the best option, health-wise - not just for tennis. They said surgery, no doubt about it. As you can imagine, this is a tough moment. It's sad to go through all this again. I didn't expect this at all.
"I cannot say anything more than that. I don't know what will happen next. Hopefully, I will have a good recovery. I hope my knee can heal properly."