Darwin Núñez and about a dozen Uruguay teammates went into the stands as fans brawled at Bank of America Stadium following Uruguay's 1-0 loss to Colombia in a Copa América semifinal on Wednesday night before security personnel stepped in to restore order.
After Colombia sealed a 1-0 victory in Charlotte, North Carolina, videos on social media showed Uruguay players climbing into the stands and exchanging blows with opposition fans.
South American football's governing body, CONMEBOL, which organizes the Copa, said it is investigating the incident and issued the following statement after the game: "CONMEBOL strongly condemns any act of violence that affects football.
"Our work is based on the conviction that soccer connects and unites us through its positive values."
Uruguay's Nuñez and Ronald Araújo were among the players at the forefront of the melee. Captain José María Giménez said the players were trying to defend their families.
"Let me say something before they cut you off because they won't let us speak into the microphone, they don't want me to say anything about what's going on but this is a disaster," Giménez said on the official broadcast. "Please be careful, our families are in the stands, there are little newborn babies. It was a disaster; there was no police and we had to defend our families.
"This is the fault of two or three people who had a few too many drinks and don't know how to drink."
Players and staff from both Colombia and Uruguay were also involved in a confrontation on the field after the final whistle.
"I thought that the incident ended with some argument on the midfield and when I saw that happening I went to the locker room," Uruguay coach Marcelo Bielsa said in a news conference.
"I thought that they were thanking the fans for their support. But then I learned that there were some problems over there unfortunately."
Jefferson Lerma's first-half header gave Colombia a place in Sunday's final against Argentina. Uruguay will play Canada in the third-place playoff.
Information from The Associated Press and Reuters was used in this story.