An attack by fans on players of top Brazilian club Corinthians has sparked outrage and promoted calls for a player strike, damaging the domestic image of the game five months before the World Cup.
"We are preparing documentation to provide legal support to players and are ready to strike -- we can't go on like this," Sao Paulo state player union chairman Rinaldo Martorelli told Estado de Sao Paulo daily.
Around 100 fans angry at the club's poor recent form attacked Corinthians' training centre as they prepared on Saturday for a state league match the following day.
The fans cut through wire netting to reach top stars including Peruvian striker Paolo Guerrero, who scored the club's winner in the 2012 FIFA Club World Cup final.
Chairman Mario Gobbi was unwilling to cancel the match against Ponte Preta, citing league and broadcast agreements.
But the attack has sparked a storm amid reports several players now want to leave the club over fears for their safety.
Also attacked along with Guerrero was Alexandre Pato, an expensive signing from AC Milan, as the fans went on the rampage -- one grabbing Guerrero around the neck while others tried to break Pato's legs.
The incident has security implications for the World Cup -- Iran will use the same training centre during the tournament.
Although football's governing body FIFA has repeatedly expressed confidence in organisers' integrated security plans for the World Cup, the incident shows Brazilian football in a poor light.
"This is not what we want to see in Brazilian football," Corinthians' coach and former Brazil boss Mano Menezes said following the incident, which saw some players have personal belongings stolen.
Folha de Sao Paulo daily said several of the squad were unhappy the club did not take a tougher line over the attacks.
But Gobbi insisted Monday that "no player has asked to leave the club."
Corinthians' poor form has riled supporters -- the attack followed a humiliating 5-1 loss to Santos.
The club had mulled going on strike ahead of this week's midweek programme, but the board decided not to take such radical action for fear the Sao Paulo league might relegate the club and broadcasters withhold revenue if it did not fulfil fixtures.
Nonetheless, Corinthians have received the support of Bom Senso (common sense) FC, the player power grouping which is campaigning for better conditions in Brazilian football, including a reduction of fixtures and financial fair play.
The latest negative publicity for the Brazilian game comes just weeks after a serious outbreak of hooliganism involving a December riot at a match between Atletico Paranaense and Vasco da Gama.
Where World Cup preparations are concerned, there have been several fatal accidents at venues still under construction and laggardly preparations could yet see the Curitiba venue dropped altogether.