Dozens of fans of the Argentine football club Huracan have stormed the club's changing rooms after a training session and assaulted some players.
They also stole players' belongings and damaged their cars outside the stadium in Buenos Aires.
The masked fans carried out the attack after a disappointing result.
Second division Huracan had been knocked out of Copa Argentina by first division opponents Godoy Cruz on penalties on Wednesday.
"We were in the showers after Thursday's training session when the disguised fans stormed the rooms and threatened the players," said coach Jose Maria Llop.
He said some of the players had been beaten.
"When we left the stadium, we found out eight cars had been damaged," he added.
The club's president, Alejandro Nadur, said the fans had come in two buses and entered the stadium.
"What they did would not have been justified, even if we had lost 15-0 to Godoy Cruz," he said.