Liverpool legend Mark Lawrenson believes Manchester United's defence is their biggest weakness.

Lawrenson wrote in the Mirror: "United are so open and easy to play against right now. In Wayne Rooney, Juan Mata, Robin van Persie and Adnan Januzaj they have an exceptional front four.

"At the back, however, Nemanja Vidic is leaving in the summer, probably Patrice Evra too, Rio Ferdinand will pack up and Rafael at right-back is just not good enough for that club.

"As a result, teams can't wait to go to Old Trafford at the moment.

"I don't care what anybody says. When players know that they are leaving or are on the way out, their level drops. They probably can't even help it, but it does."