Nani will serve a three-match suspension for his red card
Manchester United boss Sir Alex Ferguson admitted Nani deserved his red card for a two-footed challenge on Aston Villa's Stiliyan Petrov.
The sending off means United will be without the Portugal international for the Carling Cup final on 28 February.
"It was a red card. It was a naive tackle," Ferguson said of the challenge in Wednesday's 1-1 draw.
United will also be without Ryan Giggs for a month after the midfielder fractured his arm in the draw.
The 36-year-old's cross set up United's equaliser when Villa defender James Collins deflected the ball past his own keeper Brad Friedel for the visitors' 10th own goal of the season.
However, Giggs was substituted in the second half following a challenge by midfielder Steve Sidwell.
He is not a malicious player but he has gone in with his foot raised off the ground and we cannot complain about it
Sir Alex Ferguson on Nani's red card
United played for over an hour with 10 men after Nani was shown a red card by referee Peter Walton for lunging at Bulgarian Petrov, less than 10 minutes after Villa had taken the lead through Carlos Cuellar.
The dismissal was United's sixth of the season and means they will be without the in-form winger for the League Cup final encounter against Villa at Wembley as he serves a three-match suspension.
"He is not a malicious player but he has gone in with his foot raised off the ground and we cannot complain about it," added Ferguson.
"We should have had a foul seconds before when (Gabriel) Agbonlahor came in with his foot up on Wes Brown's ribs.
"That was disappointing but we have no argument at all with the red card."
Villa boss Martin O'Neill said Bulgarian Petrov is doubtful for Sunday's FA Cup tie at Crystal Palace, although the injury is not thought to be serious.
"Stiliyan is pretty sore at this minute. He thought he was going to be okay at half-time and said he would continue on, but he stiffened up," he said.
Phelan backs Nani red card
"He was unable to continue and it must be really sore if he was unable to continue. Will he be fit for Sunday? I don't know yet.
"I am sure there must be some sort of doubt about it, but we will see. The doctor said he just thinks it is a lot of soft tissue, whatever that means, but he doesn't think there is any serious damage in that sense."
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