Del Potro finished the 2018 season fifth in the rankings after winning two ATP titles and reaching the final of the US Open.
Argentine tennis player Juan Martin del Potro has returned to training, just two months after suffering a fractured right kneecap at the Shanghai Masters.
Del Potro, 30, published a video on social media in which he provided an update of his condition and showed clips of a light practice session, reports Xinhua news agency.
"I wanted to tell you this news and thank you for the support you always give me. I send you a big hug," the 2009 US Open champion said on Saturday.
Del Potro's career has been beset by injuries and a long period on the sidelines saw his career ranking plummet to 1,045th place in 2016.
He finished the 2018 season fifth in the rankings after winning two ATP titles and reaching the final of the US Open, where he was beaten by Novak Djokovic.
