Juan Martin del Potro has turned to stem cell treatment in an attempt to save his career, according to reports in South America.
The Argentinian has not played for 18 months after fracturing his kneecap for the second time in 2019.
He has had multiple surgeries in that time but none have been entirely successful, prompting him to head to Brazil in search of a more radical solution.
"Physical therapy is essential for those who receive it because it helps to reduce swelling, discomfort, as well as strengthen the muscles and help return confidence in relation to the injury," physio Luiz Fernando García explained.
"We will do some tests and see how you react to the treatment, but the immediate goal is to start with muscle strengthening exercises and seek to increase joint movements."
Last month, Del Potro's former coach claimed he did not think the former US Open winner would not come back at all, but he later poured scorn on that speculation.
"I have been fighting with my knee. It’s hard for me to come back, it’s a reality,” Del Potro said.
“I still stand by the desire to play again that I have, and I don’t think I have to close this stage (my career) yet.’
“I want to be at the Olympic Games, that makes me continue to be excited. Because of the damn pandemic, they will go to next year.
"I think it would be a prize to represent Argentina once again. That is why I am going to continue fighting.”
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