BERLIN - Claudio Reyna's hamstring is feeling fit, and Ronaldo's blisters are healed.

The U.S. captain and the Brazilian star may be ready for the beginning of the World Cup, but the status of other prominent players remains in question as the tournament's Friday start approaches.

Germany captain Michael Ballack has a strained right calf, though both he and the team's staff are optimistic the star midfielder will play Friday against Costa Rica. He felt some pain in his calf after a 3-0 win over Colombia on Friday, but didn't tell team officials until Monday.

"It's nagging, but we'll get it under control," Ballack said.

The absence of Ballack, who has 31 goals in 65 games for Germany, would be a major blow.

"Everything will be done to get him ready for Friday's game," assistant coach Joachim Loew said. "We hope that he can train with the team again soon."

The nation of England, meanwhile, is holding its collective breath regarding the fate of Wayne Rooney, who is recovering from a broken foot.

A double dose of encouraging news came Tuesday. The star striker trained with the team during its first session in Germany. He practiced free kicks and also put considerable pressure on his right foot.

The fans back in England also saw promising images when photographs taken Monday showing Rooney doing a scissor-kick volley with his injured foot appeared in the British newspapers.

"There Is A God," declared a headline in the always-understated tabloid The Sun.

Perhaps, but in England's opener against Paraguay on Saturday, there may not be a Rooney.

"The lad has had a broken foot ¡ª let him rehabilitate," England defender Gary Neville said.

England has until Friday to determine if the 20-year-old will be able to play in Germany.

"I know it's big news, he's a big football player, but let's wait until tomorrow," England coach Sven-Goran Eriksson said. "I will take a decision after that.

"It's up to the surgeons, the doctors, the specialists, but I've always said I think he will be ready."

Reyna certainly appears ready. He played Monday night in a closed-door scrimmage against Angola, his first game action since injuring his right hamstring against Morocco on May 23.

"Now it's just full steam ahead," he said Tuesday.

Ronaldo was back on the practice field, too, two days after blisters on his feet caused him to miss the second half of a 4-0 win over New Zealand.

"There are no problems anymore," team doctor Jose Luiz Runco said.

Well, there may be one. The blisters were apparently caused by Ronaldo's Nike cleats, not a resounding endorsement for a company that pays the Brazilian forward plenty to do just that.

"From what he said, maybe the type of stitching of the new cleats was bothering him," Runco said. "But they are solving the problem."

Italy defender Gianluca Zambrotta will miss his team's opening match against Ghana on Monday with a strained right thigh. Zambrotta hopes to be back for the match against the United States next week. The Italians are still unsure if defender Alessandro Nesta, who has an injured right thigh, will be available against Ghana.

Argentina defender Gabriel Heinze said he is still not in top shape after a seven-month layoff following a knee injury that sidelined him during the Premier League season for Manchester United.

"On the day of the debut, I will know if I'm not well," Heinze said. "Today I don't have an answer."

Paraguay will have to play without veteran striker Jose Cardozo, who was pulled from the squad after tearing his calf muscle on Saturday in a warmup match against Bavaria.

Cardozo will be replaced by Dante Lopez.

The absence of Cardozo puts more pressure on young strikers Nelson Haedo Valdez and Roque Santa Cruz, who is still recovering from two knee operations in the last 18 months.

The Netherlands should have five injured players back before the tournament starts.

Defenders Kew Jaliens and Giovanni van Bronckhorst, and midfielders Rafael van der Vaart, Wesley Sneijder and Philip Cocu were all still undergoing treatment for various injuries. At least four would likely start Sunday's Group C opener against Serbia-Montenegro.