The 30-year-old joined up with his country following United's thrilling 3-2 Premier League win over Newcastle United on Saturday, in which he played the full 90 minutes.
He has since pulled out, though, and returned to his club's training complex for treatment on an unspecified injury.
It remains to be seen whether Matic will be fit to face former club Chelsea on October 20.
Jose Mourinho will be desperate to have a proven performer available to him for a crunch clash at Stamford Bridge.
The Portuguese finds himself under severe pressure at Old Trafford as he prepares for a return to familiar surroundings in west London.
A dramatic victory over Newcastle last time out has earned him a stay of execution for now, with Matic among those to have talked up the need for United to keep faith with their current boss.
He has said: “The manager is trying to turn this [around], he is trying to make the team stronger and ready for the next challenge.
“I can say that in the club everyone is giving his best to do better for the team.
“It’s very hard but this is football, this is life. For sure, everyone wants to do better. We know that we didn’t play well the last couple of games. Everyone is trying to resolve this situation.”
Matic is, however, not the only United player to have offered Mourinho an untimely injury headache ahead of a return to domestic action.