The Hoops were well beaten in a 3-0 defeat at Old Trafford but their away form in the competition was unlikely to change at the home of the European champions.

While they have only collected one point from a possible 51 on the road, only Barcelona have won at Celtic Park.

And Lennox, who helped the club become Britain`s first European Cup winners in 1967, knows the vocal backing from almost 60,000 fans can inspire Celtic to greater heights.

"The atmosphere is unbelievable at Celtic Park," Lennox said.

"It`s just so noisy. When we came out the tunnel, the `Jungle` would be roaring and it was always behind you.

"I just hope the whole stadium is behind them on Wednesday."

Lennox has called for the players to be brave on the ball against Sir Alex Ferguson`s side.

"They have to stand up and be counted for a start, which most of them are good at," the former Scotland winger added.

"They have got to be brave when they have the ball, keep it as long as they can, and face up to them when they have the ball.

"But teams that come to Glasgow get it hard. We have the best support in the world and on Wednesday they have to support the team from start to finish.

"No matter how the game goes, they cannot get edgy. If the terracing gets edgy, the team gets edgy."

Meanwhile, former Celtic and Manchester United midfielder Paddy Crerand has pin-pointed winger Aiden McGeady as the main threat to the visitors.

"I know Alex tried to sign McGeady when he was about 13 and his father wouldn't let him go to England," Crerand said.

"He is a very talented player. He can give anybody problems.

"If you get someone that plays wide and can dribble, it`s very difficult.

"I think why United are so good in English football is because they have always played with two wingers.

"Sometimes defenders can`t cope with wingers because there are not many teams play with wingers any more.

"When you are playing against someone who is running at you, it`s a problem.

"How would you like to be a left-back with Cristiano Ronaldo or Ryan Giggs running at you?

"All you would want to do is kick them, and hope you kick them early enough."