Rafael Nadal is set to announce in the coming days whether he will be able to defend his Wimbledon title.

The world number one has been troubled by a knee injury and was forced to pull out of this week's AEGON Championships at Queen's Club because of fitness concerns.

Nadal himself admitted he is battling to be ready for Wimbledon, which gets under way on June 22.

And a statement on his official website, www.rafaelnadal.com, confirmed the Spaniard is having tests to determine whether he can compete at the grasscourt event.

"Rafa is in Barcelona today and tomorrow undergoing medical tests on his knees," the statement read.

"We will inform through this website the results and his participation at Wimbledon."

Nadal saw his bid for a fifth successive title at the French Open ended by Robin Soderling in the fourth round.