Manchester United manager Alex Ferguson admitted injuring David Beckham by kicking a boot which hit the England captain and said on Monday it would never happen again.
Ferguson kicked the boot, which cut Beckham above his left eye, after his side lost 2-0 to arch-rivals Arsenal at Old Trafford on Saturday in the fifth round of the FA Cup.
"It happens every night in a dressing room. It's one of those freak acts of nature. It's over, what a freak, and it'll never happen again," Ferguson told ITN television.
"It was more than just me upset in there."
Beckham arrived at Manchester United's training ground on Monday with a sticking plaster covering a cut above his left eye.
Paul Newman, spokesman for the English Football Association, said this was "absolutely not" an issue which the game's governing body would get involved in.
"You should be directing your inquiries to the club," he said.
A Manchester United spokesman said on Monday the club had no comment on the matter.
Midfielder Beckham, who had been substituted during the second-half of the match, needed two stitches in the cut and had left Old Trafford 25 minutes before the rest of the squad, according to the Sun newspaper.
Arsenal manager Arsene Wenger told reporters on Monday: "I don't like to comment on other people's dressing rooms. I don't even like to comment on my own. I think it should be secret."
Beckham and Ferguson have famously fallen out in the past including an incident two seasons ago when Ferguson ordered Beckham from the training ground after he had missed a practice session to look after his sick son, Brooklyn. He was also dropped for the next match.
The 61-year-old Ferguson is known by many players for his "hairdryer treatment".
Mark Hughes, former United striker and now Wales manager, said: "He would stand nose-to-nose with you and just shout and bawl, and you would end up with your hair behind your head."
Ferguson is not alone, however, in coming to blows with players.
Crystal Palace manager Trevor Francis was fined 1,000 pounds ($1,600) last October by the FA for hitting Latvian substitute goalkeeper Alex Kolinko around the head after the player laughed when his side conceded a goal in a first division match against Bradford City.
In 1996 Grimby manager Brian Laws broke midfielder Ivano Bonetti's cheekbone after the Italian threw food at him in a dressing-room argument. Laws escaped punishment but the two men had to make a public apology.
Ferguson signed a three-year deal in February 2002 after changing his mind about retiring at the end of last season.
United chief executive Peter Kenyon was quoted by weekend newspapers as saying the club wants to offer Ferguson a new long-term contract.
United play Juventus on Wednesday at Old Trafford in the Champions League second round.