Sir Alex Ferguson was counting the cost of a pulsating encounter with Celtic after the United manager saw Ryan Giggs limp off with a hamstring injury which will keep him out of action for four weeks.

His Manchester United side kicked off their Champions League campaign with a thrilling 3-2 victory at Old Trafford on Wednesday night.

But Giggs' injury came hard on the heels of the news that midfielder Ji-sung Park was due to undergo an ankle operation on Thursday which will sideline him for three months.