Police temporarily detained a player from a small club in northern Brazil for punching the referee after being sent off.
Television images showed Derlan charging toward referee Joao Batista Cunha Brito and striking him several times after being shown the red card. Officers rushed to the field to hold back the player.
Derlan told local media on Saturday he was sorry for what he did, but said he lost control because the referee offended his mother, who is sick with cancer.
Brito showed the red card to Derlan after his assistant said the player accused the officiating crew of making calls against his team on purpose.
Derlan, who plays for Amazon club Iranduba, could be suspended for up to 720 days for his tirade, which happened in a match last week.