Christiano Ronaldo also felt unwell before the match but is expected to have recovered in time for United's game against West Brom on Tuesday night.
"Cristiano has picked up a little bug as well," United boss Sir Alex Ferguson said immediately after the match.
"We had to get the doctor to him this morning and I didn't think he was anywhere near ready but he showed the appetite to play and it is always good to have him on the pitch.
"He will be better by Tuesday.
"We could do without these things but Ryan Giggs and Darren Fletcher are fresh, so it is just the full-backs that are giving us concern."