The San Diego Loyal walked off the field in protest Wednesday night, saying a Phoenix Rising player used an anti-gay slur directed at midfielder Collin Martin in the first half of their USL Championship match.

Martin is an openly gay player.

The game, played at Torero Stadium in San Diego, was not recognized in the league’s results from Wednesday, and the match has been ruled a forfeit.

The USL Championship said it was investigating the incident.

“We are aware of the alleged use of a homophobic slur in tonight’s match between San Diego Loyal SC and Phoenix Rising FC,” the league said in a statement. “Foul and abusive language of any type has absolutely no place in our society and will not be tolerated in USL matches. An investigation is currently underway to determine the facts surrounding the incident and more information will be provided as soon as it is available.”

In the Loyal’s previous match, Galaxy II player Omar Ontiveros was suspended by the league, and ultimately cut by the team, after uttering the N-word in the direction of Loyal player Elijah Martin.

“Last week we made it loud and clear that we do not stand for racism or homophobia. Nothing has changed this week,” the Loyal tweeted Wednesday night.

Wednesday night’s protest occurred shortly after Martin was issued a red card with the Loyal leading 3-1. Several Loyal players approached a referee and were visibly upset. One of the players could be heard saying, “We’re off the field. We’re not doing this again. F— that. We’re out of here.”

As Loyal coach Landon Donovan and Rising coach Rick Schantz discussed the situation with the referee, a Loyal player walked toward Schantz and said a Rising player directed a slur at Martin.

“Don’t act dumb,” the player said to Schantz. “You know what that means.”

Donovan later explained in a video posted on Twitter why his club chose to leave the field.

“Our guys, to their immense credit, just said, ‘We’re not going to stand for this,'” Donovan said in the video. “They were very clear in that moment that they were giving up all hopes of making the playoffs, even though they were beating one of the best teams in the league handedly. But they said that doesn’t matter, there’s things more important in life and we have to stick up for what we believe in. And so they made the decision to walk off.”

The Rising issued a statement Wednesday night and said it is “investigating the claim of a homophobic slur” used by one of its players. The Rising said the player “vehemently denies these allegations.”

“Phoenix Rising stands with the USL in rejecting and punishing any homophobic behavior,” the Rising said in its statement.

Junior Flemmings later identified himself as the player accused of using the anti-gay slur and called the accusation false, saying his teammates would support his account.

“At no point did I say a homophobic slur towards Collin Martin. I do not know Collin personally, but I respect all of my opponents equally, Collin included,” Flemmings said in a statement posted to Twitter. “I stand in solidarity with the LGBTQ+ movement.”