A Belgian side already dealing with injuries to key players saw Manchester United midfielder Marouane Fellaini leave the training field early in the final session before the Red Devils' departed to Salvador for Tuesday's Round of 16 match against the USA (4 pm ET on ESPN and Univision).

Belgium manager Marc Wilmots says that Fellaini is merely dealing with a knock to the calf, a similar injury that fellow midfielder Moussa Dembele is also carrying. But both should be ready to go against the USMNT, according to Wilmots.

Reports from Belgian reporters at training on Sunday also confirmed that Vincent Kompany (groin) and Anthony Vanden Borre (broken fibula) sat out the session, while Thomas Vermaelen (hamstring) trained on the side.

As for Vermaelen, Wilmots indicated he has noticed progress in his recovery -- "He's doing better, but we have to wait," he said -- but Kompany is a different story.

"Kompany is doing better and we'll wait to see if he can train [Monday]," Wilmots said. "But that's still a question mark as far as his participation in the match against the USA.

"Kompany has to be at 100 percent," he continued, according to David De Myttenaere of La Derniere Heure. "If not, there are other solutions. We can't just think about this match, but also long-term. We'll make the best decision."