A video has emerged showing Manchester United captain Wayne Rooney get knocked out during a boxing match with a former teammate in his kitchen.
The pair are seen playfully landing punches on each other until Rooney is hit by a blow which sends him falling to the floor.
Rooney remains unresponsive on the floor of his Cheshire mansion until the footage ends.
A friend of the footballers who filmed the incident said the fight started off playfully before getting "out of hand".
The friend told the Sun on Sunday: "Wayne had everybody worried when he hit the floor like that. He made such a thud when he went down. People were scared he had really banged his head and done some lasting damage."
The newspaper reports the incident occurred on 22 February, the day after Manchester United lost 2-1 against Swansea.
Rooney is known to be a huge boxing fan and used to train in the sport as a youngster. He said in 2008: "I think my boxing training was beneficial in my development as a footballer, especially breaking through to the Premier League at such a young age.
"I needed that extra bit of strength that the boxing training had given me. It made it easier to play than it might have been and it's helped me with the way my game is now.
"I was doing both boxing and football training at one stage when I was about 15. But Everton who I was with at the time, said I had to concentrate on one of them and I opted for football."