Portugal playmaker Deco admits he faces a battle to be fit in time for a showdown against his native Brazil.
The Chelsea midfielder, born in the state of Sao Paulo but a naturalised Portuguese, missed the 7-0 win over North Korea on Monday with a hip problem.
He has not given up hope of being ready to take on the land of his birth in their final Group G match on Friday but remains non-committal about his fitness.
Asked about his hip, Deco said: "It's so-so. I'll try to be better for the game but we'll see. I'm still having treatment and I hope to be available."
He added: "I have nothing to prove against Brazil, I just want to play and help my team. What is important now is qualifying for the next phase. We want to play well against them, we had a good game against North Korea, controlled the game and scored seven goals. We're enjoying it now, the win was important."
Deco's chances of playing Brazil seem slim regardless of his injury, with replacement Tiago stepping in and performing superbly in an excellent team performance.
Whether or not he plays, Deco acknowledges Portugal will need to be at the top of their game once more.
"Brazil is a different game, we know they are one of the favourites to win the World Cup and we'll try to do our best in the game," he said.
Tiago admits a 6-2 friendly defeat by Brazil in 2008 will be on their minds when the sides meet again.
"In the last game we lost to them in a big defeat and now we have chance to beat them," he said.
"It's not revenge, we are two great teams in the World Cup. Both teams want to go through and want to win the game, so it is not revenge, it is just a game."