Manchester United manager Sir Alex Ferguson confirmed Antonio Valencia had suffered a suspected dislocation and fracture of his ankle during the Champions League draw against Rangers.
The winger was carried off on a stretcher with an ankle injury after an innocuous-looking sliding challenge from Kirk Broadfoot in the second half of the goalless draw at Old Trafford.
Ferguson told Sky Sports: "He has gone to hospital. It looks as if it is a dislocation and a fracture.
"It's a bad one, it will keep him out for a long time. He seemed to dig his toe in the turf."