Inter Miami forward Luis Suarez appeared to spit at a member of the Seattle Sounders’ coaching staff following his side’s 3-0 Leagues Cup final defeat.
The incident happened shortly after the full-time whistle, following a melee involving both sets of players sparked by the Uruguayan.
Suarez, 38, grabbed Sounders midfielder Obed Vargas around the neck, before team-mate Sergio Busquets struck the Mexico international on the chin.
Moments later, Suarez was involved in an altercation with a Sounders staff member and was held back by team-mate Oscar Ustari before appearing to spit in the coach’s direction.
Asked about the melee, Seattle boss Brian Schmetzer said: “Unfortunately, that is going to take some of the attention away from a great performance by the Seattle Sounders.
“Their players were frustrated and that led to some things happening on the field that shouldn’t happen on the field.
“I’m going to shut that down, because that shouldn’t be the story. The story of the game is not what happened after the game.”
Inter Miami coach Javier Mascherano said: “I have nothing to say because I was far away and didn’t see what happened.
“Nobody likes for there to be these types of actions. Maybe there was provocation, but I don’t know what happened.”
Suarez has been involved in several controversial incidents during his career.
In 2011 when at Liverpool, he was given an eight-match ban after being found guilty of racially abusing Manchester United’s Patrice Evra.
He also served bans for three separate biting incidents when playing for Ajax, Liverpool and Uruguay.
Osaze De Rosario, Alex Roldan and Paul Rothrock were on target in a dominant performance by the Sounders at Lumen Field in Seattle.