Cape Town - Following a wrist injury, Rafael Nadal is in doubt for the third grand slam of the year at Wimbledon.The Spaniard was forced to pull out of after the third round at Roland Garros following the injury on his left wrist.The 14-time grand slam winner is now in a race against time to be fit for the grass court spectacle, which begins on June 27.Nadal's coach and uncle, Toni, revealed he is currently in rehabilitation and that he also has his participation at the Olympic Games in August to consider."He is in the phase of rehabilitation... we haven't fixed a date for his return because the important thing is that he returns at full strength," said the 55-year-old on Sky Sports."We also don't want to put in danger his participation in the Olympic Games."He will return when the doctors are convinced that all is going well. He won't play unless he's 100 percent."