Manchester United boss David Moyes has chosen to rest Adnan Januzaj in recent weeks in order to save the teenager from exhaustion.
Januzaj has missed Manchester United's last three games as Moyes is fearful the 19-year-old could burn out before the end of the season.
The youngster has sat out Manchester United's matches against Olympiakos, West Ham and Manchester City due to Moyes' concern over Januzaj's fitness.
Manchester United have heavily relied on Januzaj this season - despite the fact that he only broke into the Premier League champions' first team at the beginning of the campaign.
The former Anderlecht trainee has played 29 games for Manchester United in his breakthrough season, which has concerned Moyes in recent weeks.
Speaking before Manchester United's game against Aston Villa, Moyes said on the starlet: "I think Adnan has played an incredible amount of games for a 19-year-old.
"We have to be mindful of that. We have seen signs in training that we have to be careful what we do with him.
"He is a great talent and he is someone we know will go a long way at Manchester United. But we are just being careful with him.
"We have to do the right things and he has played a lot of football."
Moyes' comment will raise doubts over the possibility of Januzaj featuring against Aston Villa on Saturday as the Manchester United boss may choose to start the teenager against Bayern Munich on Tuesday.