A south Wales headteacher claims the foul-mouthed behaviour of footballers like England's Wayne Rooney is being mimicked by youngsters in class.
Rooney is a 'symptom' of pupil indiscipline, says Dr Howard
Dr Chris Howard said the on-pitch verbal abuse dished out by top soccer stars sets a poor examples for pupils.
The South Wales representative for the National Association of Head Teachers said pupils are more and more abusive.
His comments came as police study CCTV footage of a fracas between Cardiff and Millwall players on Tuesday night.
Dr Howard, headteacher at Lewis School in Pengam in the Rhymney Valley, said the morale of teachers was being eroded by the rise of indiscipline among pupils.
He claimed the way high-profile footballers behaved towards authority on the pitch was contributing to the erosion of general levels of discipline.
He said the "trigger point" for his comment was Manchester United and England star Rooney's recent verbal attack on a referee, seen on TV by more than 10 million people.
He said: "He met the referee's censure with a tirade of four letter words. You could clearly lip read what Rooney was saying - the TV commentators drew attention to the fact."
The referee told Wayne Rooney to stop swearing at him or he could be sent off.
"Instead of stopping, he continued with his foul-mouthed tirade against the referee," said Dr Howard.
He said the 18-year-old - seen as role model for millions of youngsters - was a "symptom" of the problem rather than the cause.
The on-pitch brawl was followed by incidents in the players' tunnel
He said poor pupil behaviour had become "more persistent and routine" over a period of years.
"This then gets pupils into trouble and before disciplinary panels," he said.
Earlier this month, England football coach Sven-Goran Eriksson said he would speak to Rooney about his temperament - but claimed the striker would lose much of the impact he can have for England if it was curbed too much.
Eriksson said: "You cannot take away his temperament because that is why he is such a good football player."
Meanwhile, the Football Association of Wales and the Football Association were waiting to study the referee's report of the Cardiff City-Millwall game on Tuesday night.
Three players were red-carded after a late on-pitch brawl.
South Wales Police said no criminal matters had been reported but officers were to examine CCTV footage of further incidents in the player's tunnel as well as some minor altercations between both sets of fans outside Ninian Park.