Chelsea's Eden Hazard will miss Belgium's international commitments owing to a calf injury.
The 26-year-old forward sat out his club's win at Stoke on Saturday and will now miss the World Cup qualifier with Greece and the friendly with Russia.
Red Devils boss Roberto Martinez told reporters Hazard would have to miss out, but added it was little to worry about.
"Eden has suffered an injury before the match against Stoke, it does not look so serious," he was quoted as saying in the Belgium media.
"But he will not play against Greece. We are going to follow the injury.
"It is a big disappointment for Eden that he cannot lead the team. If you want to be a good team, you have to absorb everything.
"This is a good test for us. I see enough players who can take over his role."