The young Brazilian has admitted a misconduct charge brought against him by the Football Association but has requested a personal hearing to plead his case.
However, the 20-year-old admits he was wrong to remonstrate with referee Mike Dean.
'I have accepted the charge because what I did was wrong,' he said. 'It happened because I was so frustrated at being sent off in such an important game. I apologise for my behaviour.'
Not going quietly: Rafael (left) protests after his dismissal against Tottenham
By pleading guilty to the improper conduct charge Rafael hopes that the FA will not increase his punishment when they hear his case on Friday.
Rafael already knows he will miss United's Premier League encounter withBirmingham at Old Trafford on Saturday.
However, a disciplinary panel on Friday could add an additional game to his punishment and rule him out of next Tuesday's trip to Blackpool.
Alternatively, he could be fined or simply warned about his future conduct.Rafael lost his cool when Dean decided his trip on Benoit Assou-Ekotto during the second half of Sunday's goalless draw was worthy of a second yellow card.
The youngster clearly disagreed and will take heart from the fact both managers felt the same way.
'It's not worth discussing because everyone can see it,' Sir Alex Ferguson said after the game. "It's out of my bounds now. Thank God.;
Even Spurs boss Harry Redknapp described the decision as 'harsh'. He added: 'It was like Mary Decker and Zola Budd in the Olympics a few years back.'
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