Manchester United manager Sir Alex Ferguson has revealed that he leaves it up to the club doctor to decide whether his players can take sleeping tablets.

Liverpool defender Glen Johnson revealed during the week that many of the England players that had played in Wednesday's 1-1 draw with Poland had taken sleeping tablets prior to the game.

Ferguson said: "I think some players do take sleeping tablets at night.

"I don't know which ones. There are all different types and some very mild ones. I leave it to the doctor."

Manchester United take on Stoke City on Saturday afternoon.