Assistant referee Alex Verstraeten admits he and his colleague Peter Hermans wrongly allowed two of Manchester United's goals in the Champions League clash on Tuesday. The Bhoys lost 3-0 at Old Trafford but The Reds opening two goals through Dimitar Berbatov appeared to be offside.

"This is the first time we have made a mistake in 52 international matches," Verstraeten told the Daily Record.

"I can deal with such comparisons. We have not yet talked about it as a group. I admit to the mistakes, but we also ask for understanding.

"Offside decisions are the hardest to judge. We are only human flesh and blood.

"It is just our bad luck that the mistakes came in incidents that led to goals.

"We made mistakes and that should not happen and we also know it is of no consolation to Celtic that Manchester United would have won with or without these decisions."

Verstraeten argued that the fact Celtic's players did not protest the goals shows how hard the decisions were to make.

He added: "Some players argue their case in front of us. But no Celtic player protested at the time.

"That proves the offside decisions were very tight.

"I have to admit that at the end of the match I was very surprised when I saw the television images."