WIMBLEDON, England — Rafael Nadal figured he couldn’t win Wimbledon this year because of his achy knees, so he decided it didn’t make sense to try.

Nadal withdrew from the grass-court Grand Slam tournament Friday, three days before it begins, becoming only the second men’s champion in 35 years to decline to defend his Wimbledon title.

“When I start a tournament like Wimbledon, it is to try to win,” the No. 1-ranked Nadal said, “and my feeling right now is I’m not ready to play to win.”

A subdued Nadal, wearing a purple T-shirt and white pants, spoke at a news conference Friday evening at the All England Club, in the same room where he took questions after beating Roger Federer in the epic 2008 final that ended after 9 p. m. with light fading.

He announced his withdrawal about 2z hours after losing to 18th-ranked Stanislas Wawrinka in an exhibition match on grass at Hurlingham Club in south London.

“Today was the last test. I didn’t feel terrible but not close to my best,” said Nadal.

In other pre-Wimbledon action, defending champion Tamarine Tanasugarn upset top-ranked Dinara Safina, 7-5, 7-5, Friday in the semifinals of the Ordina Open in Den Bosch, The Netherlands.