Manchester United boss Sir Alex Ferguson says the match officials are confused over the ruling of physical challenges.

The clash between Andy Carroll and David de Gea at Upton Park sparked heated discussion about the use of video to bring retrospective action.

"I don't know where they are now. I really have no idea,'' said Ferguson.

"I don't think there is any clarity now.

"It's difficult to go through all the ones you're talking about.

"I think it was a red card - I don't think there is any dispute.

"I think Sam has masked that by talking about being robbed in the game. That masked the fact they should have had 10 men.

"But it didn't happen and it doesn't bother me now. It's gone, it doesn't affect us anymore.''