Juan Martin del Potro: 'Wrist injury casts doubt on future'

Juan Martin del Potro has admitted that he doesn't know what his future holds after suffering another injury setback in Dubai.

The 25-year-old was forced to retire in the opening round of the Dubai Tennis Championship on Tuesday due to a wrist problem, which he has compared to the injury that kept him out of action for nine months in 2010.

"I cannot say that [it will be surgery] yet - but I'm feeling similar pains to the other hand and what I felt four years ago," Del Potro revealed to reporters.

"It's not really positive for my future. But I will do whatever the doctor says and I will have to be as strong as ever.

"My wrist is hurting a lot, and, you know, everybody knows what's happened to me four years ago with my other wrist."

Del Potro is currently fifth in the ATP rankings.