Sir Alex Ferguson has admitted the four-match ban imposed on Patrice Evra for his part in the post-match fracas at Stamford Bridge last season left him stunned.
The Manchester United full-back was also fined £10,000 after the FA found him guilty of improper conduct following a two-day hearing last week.
It means Evra is now due to miss all domestic duty until Chelsea's visit to Old Trafford on 11 January.
United chief executive David Gill is still waiting for written confirmation of the ban and the reasons behind it before deciding whether to appeal.
However, despite a long list of battles with Soho Square chiefs, Ferguson feels their latest punishment is the most staggering yet.
"It was a shock," said the Scot.
"Of all the things the FA have done to us down the years that was one of their biggest. I could not believe it.
"You could never tell what these people are doing. Even if I was sitting having breakfast with them I would not know what they were thinking.
"But we are still waiting for the written reasons to be delivered to David Gill so we cannot really comment on what our next step will be."Reuse content