Manchester United have submitted a claim of mistaken identity to the Football Association after Fabio da Silva was booked by referee Chris Foy against Barnsley in the Carling Cup.
Instead the offender - for a challenge on Jamal Campbell-Ryce - was his twin brother Rafael.
The FA confirmed they have been approached by United and the submission will be heard on Tuesday by a regulatory commission.
The Brazilian twins helped United secure a place in the quarter-finals of the competition thanks to a 2-0 victory. However the holders finished the game with ten men after Foy sent off Gary Neville for clattering into Adam Hammill.
Meanwhile, Peterborough boss Darren Ferguson has received a favour from his famous father, Sir Alex, after signing Ben Amos on a month's loan.
Ferguson has raided United and signed 19-year-old Amos with first-choice goalkeeper Joe Lewis suspended for this weekend's clash against Barnsley.
Ferguson told BBC Radio Cambridgeshire: "It's a big game for him and he knows that. He'll be fine though. He comes well recommended. My father [Sir Alex] thinks very highly of him."