Ferguson has been suffering from the virus since United’s flight home from the clash with Bursaspor on Tuesday.
Darron Gibson is also suffering from a virus.
“The manager has been ill since coming back from Turkey,” said United assistant manager Mike Phelan.
“He came down with a virus yesterday. He felt a little bit like that on the flight coming back.
“Yesterday he felt worse, so we have kept him away from the club for a little while.
“It is related to the virus that has been going around.
“It is one of those things that gets hold of you and is hard to shake off but he will be at the game tomorrow.”
