Roque Santa Cruz's participation in Paraguay's World Cup opener against England is again in doubt after he limped out of training on Wednesday.

The Bayern Munich striker missed most of the Bundesliga season with a serious knee injury and his participation in Paraguay's preparation for Germany 2006 has been severely restricted by tendinitis.

Santa Cruz declared himself fit to take on Sven-Goran Eriksson's men on Tuesday, only to experience pain in his left knee the following day.

"I hope I will be okay. If I don't feel well, I won't start the game," the 24-year-old said.

Paraguay's medical team refused to comment on the seriousness of Santa Cruz's condition, while coach Anibal Ruiz would only say he planned to wait until the morning of the game to make a final decision about his star striker's participation.