A video has emerged showing Manchester United captain Wayne Rooney seemingly being knocked unconscious during a boxing bout with one of his former teammates.

The incident is said to have taken place in the 29-year-old's Cheshire mansion the day after the Red Devils' 2-1 defeat away at Swansea City in the Premier League last month.

Rooney is seen lying on the floor following a blow to the face from Stoke City's Phil Bardsley, and according to The Sun, the publication which published the footage, the England international could now face the full wrath of manager Louis van Gaal.

It is claimed that Rooney was left feeling "shaken" by the heavy punch, with a source telling the newspaper: "Wayne had everybody worried when he hit the floor like that. He made such a thud when he went down and he was just on his back with his eyes closed, not moving."

"People were scared he had really banged his head and done some lasting damage. Everybody realised it was a stupid thing to do, but they just got carried away."

Rooney is rumoured to be on a £300,000-a-week contract at Old Trafford.