A group of fans upset with Palmeiras' poor results attacked one of its players outside the team's stadium, leading the Brazilian club to postpone Wednesday's league game against Flamengo.
Brazilian police said supporters of one of the team's organized fan groups punched and kicked reserve midfielder Joao Vitor after he was recognized arriving at the team's official store outside the Palestra Italia stadium on Tuesday.
Joao Vitor sustained minor injuries and had to visit hospital briefly.
Palmeiras lawyer Andre Sica told local television the fans confronted Joao Vitor over the team's recent results and the verbal altercation escalated into a physical confrontation. The 22-year-old player was with friends, who also got involved in the fight before police intervened with no arrests made.
Joao Vitor, who regularly comes off the substitutes bench, was not originally scheduled to travel with Palmeiras because of an injury.
Organized fan groups in Brazil are known for being violent and are often involved in confrontations with police and rival groups.
Palmeiras players and fans have a history of getting into disputes as former Brazil striker Vagner Love left the club after receiving threats.
Eight-time Brazilian champion Palmeiras, led by World Cup-winning coach Luiz Felipe Scolari, is ninth in the league standings after winning only one of its last nine matches to trail leader Corinthians by 11 points.