Scholes was injured just 16 minutes into the Red Devils' 3-0 Champions League win and it immediately became obvious that he could not continue.
Manager Sir Alex Ferguson suggested after the game that Scholes would be missing for about eight weeks but after being assessed by club medical staff on Wednesday, the damage is even worse.
If the current diagnosis proves accurate, Scholes will not be available again until the visit to Tottenham on December 13, which comes immediately before United head to Japan for the World Club Championship.
It means Scholes will miss the rest of his side's Champions League group campaign, plus key Premier League away games at Everton, Arsenal and Manchester City.
In total the 33-year-old could miss 16 matches from United's season.
It is a blow for Ferguson even though he has plenty of cover despite the fact Michael Carrick and Owen Hargreaves are currently on the sidelines as well.
Scholes remains one of the most influential players in the Premier League and was outstanding as a second-half substitute during Saturday's win over Bolton.
Three years ago the former England man overcame a serious eye problem many felt could end his career.
Ferguson still rates Scholes as one of his key men and will no doubt be keen to have him back for the second half of the campaign.
