Juan Martin del Potro admits he is still not 100% fit but will continue his fight to get back to the top of the game.

The 2009 US Open champion has been plagued by injury over the last few years, undergoing surgery on both of his wrists in a bid to return to his former level.

When fit, Del Potro has proved he can still match the best, most memorably taking Novak Djokovic to five sets in the semi-finals of Wimbledon in 2013.

The 27-year-old is currently in the midst of his latest comeback and impressed in beating Gilles Simon and Grigor Dimitrov on his way to the semi-finals last week in Stuttgart.

He is now due to face John Isner on Tuesday at the Aegon Champions, a match he is 1.62 to win, with the American 2.15, before switching his focus to Wimbledon.

Del Potro admits he is still to reach his peak fitness but is simply happy to be able to play again.

The Argentine says he will continue to manage his wrist issues and for now his main goal is to cause as many problems as possible against the top players.

He said: “I am happy that I am back playing tennis again after three operations, two years without competing… I was at home very sad but now my reality is totally different.

I am enjoying tennis again and I share it with all you.

“I have to deal with this wrist issue at the moment, I will keep working and in the future I hope to be a tough player for all the players.”