The 33-year-old midfielder was stretchered off after just 16 minutes of United’s 3-0 Champions League win over Aalborg.
United also face an anxious wait on Wayne Rooney who picked up an anke injury and has been rated as doubtful for Saturday’s trip to Blackburn.
Sir Alex Ferguson has already virtually ruled Rooney out of United’s league encounter with Blackburn at Ewood Park on Saturday an there must be doubts as to his availability for England’s forthcoming World Cup qualifiers against Kazakhstan and Belarus.
“Wayne felt a weakness in it when he went to receive a ball and we took him off straight away,” Ferguson said. “So there was maybe a cost to pay for the victory.”
“We hope it is not ligament trouble – but he is doubtful for Saturday, I would imagine.”
Ferguson is already resigned to the prospect of losing Scholes for up to two months. “We do not know exactly how serious at this moment in time,” said the United boss
“Scholes has suffered a medial knee ligament injury and we won’t know for 24 hours how bad it is.
“But it could keep him out for six to eight weeks and that is bad for us.”
“It looks like medial ligament damage, which would be six to eight weeks – a bit of a blow.”