Sir Alex Ferguson is yet to decide whether to appeal against his five-match touchline ban - and is worried about Rio Ferdinand's fitness.
Ferguson learned of his punishment for comments made about referee Martin Atkinson following United's 2-1 defeat at Chelsea earlier this month after a disciplinary hearing on Wednesday.
He has vowed to defend himself strongly and the outcome was clearly a shock.
"It is disappointing," he said. "It is the only industry where you can't tell the truth. But it is in the past now."
Meanwhile, Ferguson has also suggested England defender Ferdinand could be facing a longer spell on the sidelines than had originally been envisaged when he suffered a calf injury in the warm-up ahead of United's surprise Premier League defeat at Wolves on February 5. He could even miss the rest of the season.
"Rio has been out for a few weeks now," said Ferguson. "We are not looking at this as a short-term situation.
"He has not started training yet. We will be lucky to get him back for some part of the season."
Ferguson confirmed that Republic of Ireland defender John O'Shea, who limped out of Tuesday's Champions League win over Marseille, had been ruled out for five weeks with a hamstring injury.
"It's not a good one," said Ferguson, who will also be without skipper Nemanja Vidic for Saturday's encounter with Bolton at Old Trafford.
Rafael, meanwhile, faces three weeks on the sidelines, also with a hamstring injury.
