Jason Denayer has not appeared for Manchester City's first team but has had loan spells at Celtic, Galatasaray and Sunderland. Matthew Ashton - AMA/Getty Images

Belgium international Jason Denayer has apologised for his behaviour after he was filmed kicking a man in the head during a fight in Brussels at the weekend, insisting he "reacted instinctively" to one of his friends being attacked.

The Manchester City defender, who spent last season on loan at relegated Sunderland, was in Belgium at the weekend and was involved in an incident outside a bar on Sunday that was caught on film.

"I reacted instinctively," the 21-year-old was quoted as saying by BBC Sport.

"Of course I regret to have been caught up in a conflict that was not mine to begin with, but I saw my friend was in real danger and I had to interfere and protect him."

Denayer's agent, Jesse De Preter, said in a statement that the player had been defending a friend during the brawl.

De Preter told Belgian newspaper Het Laatste Nieuws: "His reaction could be perceived as aggressive, but it's clear it was a defensive one. What you don't see on one of the videos is that the person who gets the kick is beating Jason's friend to death. His reaction was purely in panic and to protect his friend. Jason wanted to stop the violence.

"Jason had two days off this weekend, with permission of his club. He decided to go out with his best mates. When they left the club, it all went wrong.

"Jason was walking towards his car, a bit further down the street, when he suddenly heard a lot of noise. When he turned around, he saw that his friend got caught up in a brawl. Jason shouted and called up to stop the fight, but without any effect.

"Only when he saw his friend was really beaten-up, he decided to react. It's true that he has kicked someone, but it was a defensive reaction.

"As soon as his friend was safe, they left the scene. He ran to his car. His car was half demolished too, but he managed to drive away. He is in shock after what happened.

"In a second video you can see that he only reacts when he sees that his friend is in trouble. Jason didn't have any malice in him."

Denayer, who has a contract with City until 2020, is expected to go out on loan for another season.