Ray Wilkins branded Manchester United's draw for the last-16 stage of the Champions League as "horrible" after they were paired with nine-time winners Real Madrid.
Sir Alex Ferguson's side strolled through the group stage, finishing top of a pool that included Galatasaray, CFR Cluj and Braga, but face a daunting challenge against Jose Mourinho's charges, who finished runner-up to Borussia Dortmund in their group.
And former Manchester United midfielder Wilkins fears Real's arsenal of attacking players, including former favourite Cristiano Ronaldo, could be too much for the English side to cope with.
"Real Madrid are a wonderful team so it is a horrible draw for Man United," Wilkins told Sky Sports News. "But it will be a classic game between two of the greatest sides in world football.
"United go to Madrid first and have to come back to Old Trafford with half a chance, because if they go to the Bernabeu and get annihilated, as other teams have been, it could be extremely difficult for them.
"Plus, I think Real have far more attacking options that can hurt United than United have that can hurt Real."
Manchester United have won just two of their eight meetings with Real Madrid, but Sky Sports pundit Jamie Redknapp believes the Spanish giants are not as strong as last season, when they claimed the La Liga crown and reached the Champions League semi-finals.
"Real are 13 points behind Barcelona and that shows you how much they have slipped since winning the title last year," said the ex-Liverpool and Tottenham midfielder.
"They have added Luka Modric, who I thought would do better, and there certainly seems to be problems behind the scenes.
"However, if this is to be Mourinho's last year he would love to sign off with a Champions League trophy and I'm sure this will be billed as his audition for the Man United manager's job - and if he has got his eyes on that, he will be on his best behaviour.
"Ronaldo, meanwhile, is one of the great players in the Premier League era and will get a huge welcome on his return (to Old Trafford)."