Brazil striker Fred fears there could be “another tragedy” in Brazilian football if supporters carry out their threats against his club this week.

In a letter posted on his Facebook and Twitter accounts, Fred said he is concerned about what could happen to him and his teammates if Fluminense don’t reach the second round of the Brazilian Cup on Thursday.

He said a group of about 20 fans threatened him as he left training this weekend, complaining about the team’s recent form and demanding an improvement.

“After ‘the message’ this weekend, when a group of dropouts disguised as fans threatened the team’s players, Brazilian football could be about to witness another foretold tragedy on Thursday if Fluminense fails to advance past Horizonte in the Brazilian Cup,” he said.

Horizonte, a little known club, won the first leg 3-1 and are a draw away from reaching the second round.

Fluminense were also eliminated by rivals Vasco da Gama in the semi-finals of the Rio de Janeiro state championship last week, a result that prompted team officials to fire the coach.

Fred mentioned other recent cases of fan violence in his letter, including the death of 14-year-old Bolivian Kevin Espada, who was hit in the head by a flare launched by fans of Brazilian club Corinthians. He also recalled when Corinthians fans invaded the team’s training ground to threaten players, and the death of a Santos fan attacked by Sao Paulo supporters.

“How many more Kevins will have to lose their lives, how many training centers will have to be invaded, how many innocent people will have to be beaten to death until something serious is done against these barbarians?” Fred said. “Or will we have to wait until a player is beaten?”

The striker said it’s not a coincidence there are now empty seats at grounds, where “the flags that used to wave in stands have become weapons in the hands of these bandits.”

Fred said from now on he would not celebrate in front of the fan groups.

“I’ll fight with the weapon that I have,” he said. “Starting today, I will not celebrate my goals near the fan groups. I’ll dedicate my goals to the real Fluminense fans.”