Victor Lindelof missed training on Monday as Manchester United prepare to face Young Boys in the Champions League.
The Sweden international played through the pain barrier on Saturday as United drew 0-0 with Crystal Palace at Old Trafford.
Jose Mourinho subsequently lamented the fact that Lindelof had sustained an injury while playing for his country; the defender played 90 minutes against Russia after being withdrawn at half-time against Turkey due to illness.
The 24-year-old was in visible pain during the closing stages of the game but United had used up their substitutions, so he played on, and Mourinho later alluded to the fact that he was likely to be out for this week's European encounter.
“I believe [he is injured]. I have to believe so," he told MUTV.
“I always say this is the period of the injuries. If they are not injured with the national teams, they come to the clubs and are injured.
“He played against Russia three days ago or two days ago, but of course, we need him when he plays.
“He was probably our best player. He was a brave lad, but he probably punished himself."
Marcos Rojo was also absent from training, as he continues his recovery from a knee injury.
The Argentina international has played just 54 minutes of football thus far this season - in an Under-23 game against Reading - and is yet to feature for the senior side in 2018-19.
He was named on the bench for the 2-1 win over Everton in October but has since failed to appear in matchday squads.
Matteo Darmian is also likely to miss the game, having appeared just twice this season, in the first game of the campaign, versus Leicester, and the most recent, against Palace.