Cristiano Ronaldo's chances of being fit for Portugal's opening World Cup clash with Germany were thrown into further doubt when coach Paulo Bento refused to put a timeframe on his return.
Ronaldo, 29, failed once more to train with the rest of his teammates, as they went through their paces ahead of Friday's friendly with fellow World Cup qualifiers Mexico in the United States.
Portugal play the strongly fancied Germans on June 16 but, at this rate, they could be without their star player and talisman, who was already ruled out of the Mexico game because of persistent leg injuries.
The Real Madrid forward has a left thigh injury and tendinitis in the knee of the same leg, and has been struggling for fitness for several weeks in the crucial build-up to the Brazil showpiece.
Even if Ronaldo is free of injury, it looks increasingly unlikely that he will be match-fit.
"The situation is evolving and our expectations are evolving constantly," Bento told reporters at the Foxborough stadium of the New England Patriots, asked repeatedly when Ronaldo would be fit.
"When he's ready to play is a decision that will be made just like any other player, regardless of who it is.
"I'm not at liberty to discuss at full length the situation. As soon as he is ready to train, we will make that announcement."
Growing visibly frustrated by persistent questions about Ronaldo, Bento added: "We have to prepare for Germany regardless.
"The decision of if he will play and when is up to me, the player and the doctors. Ronaldo is not the only good player we have."
Ronaldo, who has scored 49 goals in 110 matches for Portugal, also missed the goalless draw with Greece on Saturday in Lisbon.
Portugal, who squeezed into the World Cup via a playoff with Sweden, face a mounting injury crisis - key defender Pepe and experienced midfielder Raul Meireles are also out of the Mexico encounter.
Real Madrid's Pepe has a left leg injury, although indications are that he will be fit for the World Cup.