Tom Cleverley is a doubt for both Manchester United and England after he was sent for a scan on an injury he picked up in Thursday's game against Ajax.
The midfielder, who was returning to action after four months out with a foot injury, came off after 60 minutes of the Europa League game, being replaced by Paul Scholes in a 2-1 defeat that nevertheless saw United progress to the next round.
Cleverley was hoping to pick up his first England cap next week, after being named in Stuart Pearce's squad for England's friendly against Netherlands at Wembley. While Ferguson does not believe the problem is serious, the desire to prevent another long-term lay-off may force the 22-year-old to miss United's Premier League game against Norwich this weekend - and the international friendly at Wembley in midweek.
"He got a knock," Ferguson said. "We sent him for a scan but we don't think it's serious."
Cleverley knows Pearce from his time in the England Under-21s, and had been hoping to make an impression on the international stage ahead of the forthcoming European Championship.
"I don't really listen to what people are saying. I just go out and play my football," Cleverley said recently. "If I can find some good form from now until the end of the season, I would be more than happy to be involved in the European Championship.
"I am not sure whether it is a good time though. I know Stuart Pearce quite well from my time with the Under-21s. He is a good manager. Hopefully I will be involved."