Two days away from a match that will likely decide both team’s World Cup fates, and there are still questions surrounding Portugal megastar Cristiano Ronaldo and his aching left knee ahead of Sunday’s matchup with the United States.

According to reports, the 29-year-old with a record 49 goals scored in 112 senior team appearances again wore a brace on his shaky knee during training Friday. He took part in some light drills and appeared in good spirits throughout Portugal’s last session before departing for Manaus for the pivotal Group G game.

Ronaldo has remained determined to play despite reported warnings from the team’s physician that he’s putting the rest of his career in jeopardy. Much of the motivation might have to do with Portugal’s humiliating 4-0 loss to Germany in its World Cup opener and Ronaldo’s overall legacy.

His domestic career cannot be questioned as Ronaldo holds records for most goals scored in a single Real Madrid and La Liga season, as well as a recent Champions League title. Lifting Portugal to the World Cup title would cement Ronaldo’s place among the sport’s elite, while an early exit leaves him ripe for criticism.

Portugal’s best finish in the World Cup was fourth in 2006 in Germany, Ronaldo’s first go-round in the tournament.

The controversy surrounding whether Ronaldo will or will not play has also consumed the rest of the team.

"I have already answered so many questions about Cristiano Ronaldo. Actually we speak about him every day. If I am sick of it, imagine how he is feeling," forward Heider Postiga said to the Associated Press. "If he is available enough to train with us that's probably because he is feeling well. He's been training with us all these days and as usual he always gives his best. He's just fine."

U.S. head coach Jurgen Klinnsman also has some injured players to worry over, but an absent or even limited Ronaldo gives the Yanks a huge advantage.

Record-setting U.S. forward Clint Dempsey is expected to play after suffering a nasal fracture during the 2-1 upset victory over Ghana. The 31-year-old Seattle Sounders star and Texas native may wear a mask to protect his nose, but the injury isn’t expected to affect his play.

Starting defender Matt Besler suffered a hamstring injury versus Ghana and was pulled more as a precaution, but he’s also expected to play Sunday. However, removing Besler and inserting John Brooks proved to be the move of the match with Brooks’ late wonder goal putting the U.S. in position for second or even first in the group.

Klinnsman must also decide who will replace striker Jozy Altidore in the starting lineup. A powerful forward capable of barreling over defenders, Altidore strained his left hamstring in the 21st minute against Ghana, and the U.S. announced Thursday that he would not make an appearance against Portugal. Altidore could still compete in the group play finale against Germany.

Next up on Klinnsman’s depth chart is Aron Johannsson and Chris Wondolowski. The latter has far more international experience, but believes both players are ready to take on the difficult task of filling in for Altidore.

"It's a big loss losing Jozy, he's been playing really well and is in great form but I think our roles are going to stay the same," Wondolowski said Friday to reporters. "I know for myself and Aron that we're both going to be ready to play at any minute and just looking for the opportunity and making the most of it whenever we get the chance."