Nadal pulls out of Croatia Open because of knee injury

UMAG, Croatia (AP) - French Open champion Rafael Nadal said Monday he pulled out of the Croatia Open because of a knee injury.

"I have had problems with my knee for a few tournaments and it is hurting more now, so I have to cancel to not finish on the operating table," Nadal told reporters.

Nadal, who won his eighth season title on Sunday at the Mercedes Cup with a 34th straight victory on clay, arrived at the ?340,250 tournament to explain his withdrawal - and apologize on center court later in the day.

"I played here two years ago and really love this tournament. I keep planning to come back but something happens," Nadal said.

The 19-year-old Spaniard said his injury is not serious but could be aggravated if not rested.

"It is tendinitis and it could get serious if you do not take care of it," he said.

Nadal has reportedly been taking painkillers.

Guillermo Coria, who helped Argentina defeat Australia in the Davis Cup quarterfinals last weekend, takes over as the top-seeded player at the tournament, which starts Monday.

The field includes three-time French Open champion Gustavo Kuerten, Carlos Moya and clay-court specialist David Ferrer.