It has emerged that referee Chris Foy booked the wrong da Silva win during Man United’s 2-0 win over Barnsley. Fabio played in central defence and Rafael was playing in midfield.

Foy booked Fabio for a challenge on Barnsley’s Jamal Campbell-Ryce, but it was Rafael who fouled the player.

A United spokesman said: "We are in discussions with the FA over this matter.

"We have pointed out that the referee made a mistake on the night and we obviously want it to be corrected.

"We will be asking for further advice on how best to rectify the situation."

Man United manager Sir Alex Ferguson has said that the only way he can tell the difference between the 19-year old identical twins is a wedding ring. Fabio is married so he wears a ring, that doesn’t always work. There have been a few reports suggesting that occasionally Rafael wears the ring.

Obviously, neither of them can wear it on a football pitch, but they do wear shirts with their names and numbers on the back.