Nadal's knee to be checked next week

Defending champion Rafael Nadal is in doubt for Wimbledon because of a knee injury, his coach said Saturday.

"We will see on Monday or Tuesday. We will go to Barcelona to see what the problem is. I am not too optimistic," the world No. 1's uncle and coach, Toni Nadal, told French radio RMC.

"Of course, if there is a possibility for him to take part in one the world's greatest tournaments, he will.

"He is very affected by this."

The Spaniard had already pulled out of next week's Wimbledon warmup grass-court tournament at Queen's Club and now faces the possibility of missing the season's third Grand Slam, which begins on June 22.

Nadal's four-year reign at the French Open was ended by Swede Robin Soderling in the fourth round.