Juan Martin del Potro admits he feared the worse when fracturing his kneecap at the Shanghai Masters in October but says he is now ready to return to action.

The Argentine star has struggled with a number of injury issues in recent years but rediscovered his form in the first half of 2018, claiming a first ATP Masters 1000 title at Indian Wells while reaching a career-high number three in the ATP rankings in August.

Del Potro has been absent since his injury blow in October but is set to make his return in the Delray Beach Open against Yoshihito Nishioka.

The 30-year-old, now ranked as the world number four, feels it will take time to rediscover his best form but is delighted to be back in action after missing the ATP Tour Finals and the Australian Open.

“I thought that was the final [match] of my life [in Shangai]. I got the fracture in the knee that I never expected to have,” said Del Potro.

“After bad days I started believing in my doctors again that I’ll play tennis soon and I think I’m in a good way again to be competitive.

“After four months, I’m going to be playing a tournament, which is good [recovery] time. But I know how difficult it is to be ready for playing in the big events and holding the top positions in the [ATP] Rankings and I know this way because I had it in the past. But this is my life and I know how to deal with these problems.”

Del Potro claimed his only Grand Slam title at the US Open in 2009 and he is 13.00 to win the event this year, Rafael Nadal is 5.50 and Roger Federer is 7.50.