Manchester United boss Ole Gunnar Solskjaer admits Luke Shaw has a hamstring problem.
Shaw was forced off during the friendly win against Perth Glory.
Solskjaer said, "Luke he felt his hamstring was a little bit tight, so there was no point taking any more risk.
"You saw him still after he made a signal that he wanted to come off, he still kept on running, so it's not a bad one I think. It was just a precaution. We've been working hard and he felt some tightness there, so we'll have to assess him and probably rest him for a few days."