An impromptu party thrown by jubilant Czech players last week after they qualified for Euro 2012 has marred the team's image just six months before the tournament kicks off in Poland and Ukraine.
After beating Montenegro twice in the European Championship playoffs, squad members insulted an ex-international who had criticised the team, before going on to tear up their clothes on the plane home from the Montenegrin capital Podgorica.
"Instead of savouring the euphoria, we have found ourselves facing a problem, which has devalued our success," said Miroslav Pelta, new head of the Czech Football Association.
The Czech Republic, 1996 runners-up and third-placed in 2004, beat Montenegro 2-0 at home and 1-0 away to book a ticket to their fifth straight Euro tournament.
In the small hours of last Wednesday at Podgorica airport, players formed a circle and started a chant suggesting former international striker Radek Drulak did not have genitals, in a scene that has become a YouTube hit.
Drulak, a member of the Czech's Euro 1996 team, had slammed the current squad several times for an alleged lack of style during the Euro 2012 qualification campaign.
The players then tore their official suits and, on arriving home, some marched through Prague's airport lounge half-naked.
"Such behaviour cannot be tolerated if you're a national team player," said Pelta, as the association fined the team two million Czech koruna (78,000 euros, $106,000) on Monday.
Pelta also declared "zero tolerance" for such incidents, promising "severe and uncompromising steps" against future culprits.
"We would definitely suspend someone if this happened again," he said.
Arsenal midfielder Tomas Rosicky, the team captain, apologised for the incident on Sunday evening.
"Uncontrollable emotions and euphoria gained the upper hand over common sense, for which I want to apologise," he said, adding he "was not proud" of the incident.
The players' actions also angered Czech fans, some of whom have called for a tournament boycott.
The tarnished image was underlined by team manager and former Lens, Liverpool and Bordeaux midfielder Vladimir Smicer.
"I'm sorry the boys went out of their way to settle their accounts in this unfortunate way," Smicer told AFP.
"Of course I'm sorry we spoiled the fun for fans. We have half a year to boost our image... and go to the tournament as one team," he added.
The national team already fell out of favour with its fans in March 2007.
At the time, several players threw a wild party allegedly involving prostitutes in a Prague hotel following a loss to Germany in the Czechs' Euro 2008 qualifying campaign.