Manchester United defender Mikael Silvestre has been ruled out for three weeks with ankle ligament damage.
Silvestre limped off during the first half of Saturday's 1-1 draw with Leeds after coming off worst in a 50-50 collision with Alan Smith.
Sir Alex Ferguson expressed his concern over Silvestre's chances of making Wednesday's Champions League trip to Porto and his fears have been realised with confirmation of the extent of the former Inter Milan player's injury.
"Mikael will be out for three weeks," Ferguson told the Manchester Evening News.
"It is a big blow for us but we will just have to get on with it."
The news is likely to see skipper Roy Keane moved into a central defensive role in Portugal on Wednesday.