Former US Open champion Juan Martin del Potro said he almost quit tennis after a succession of wrist injuries but still hopes he can regain his former powers.

Argentinian Del Potro, 27, returned to the tour in February nearly 11 months after undergoing wrist surgery for the third time, reaching the semi-finals at the 250 Series Delray Beach Open.

Results since have been a little disappointing but after plumbing the depths the past two years at least he is able to play relatively pain free.

“I was close to quitting tennis. I got frustrated at home and I didn’t watch tennis on TV because it was sad for me,” Del Potro said.

“It was close. But now, I have many good things to take from the tour. I would like to play tennis and that’s it.”

Del Potro reached number four in the world in 2009 and was expected to follow up his US Open triumph with more grand slam titles only for his injuries to strike.

Despite being a right-hander, Del Potro’s left wrist has been the source of his discomfort, preventing him striking his trademark double-fisted backhand drive.

It first troubled him in 2010 when he endured a nine-month break from the game after surgery.

He recovered to return to the world’s top five by 2013 when he played an epic Wimbledon semi-final against Novak Djokovic.

However, since the start of 2014 he has completed only 22 matches with two more bouts of surgery required to his tendon.

Despite pulling out of the Miami Open, which finished on Sunday, after feeling some discomfort in the wrist, Del Potro remains upbeat.

“Hopefully after my third surgery, the problem is almost fixed and I am here, playing tennis again,” he said.

“I’m still confident in my game and still looking forward to playing with the top guys in the same condition, not like (Indian Wells), when I couldn’t hit my backhand at 100 per cent. Maybe in the future I will get that chance.”