The U.S. Soccer Federation, citing insufficient evidence, will not levy any sanctions in an alleged instance of racial abuse from the U.S. Open Cup quarterfinal between LAFC and the Portland Timbers on July 18.

After LAFC won the match 3-2, forward Adama Diomande alleged on Instagram that a Portland player directed a racial slur at him during the match.

The USSF and MLS commenced with an investigation, and the U.S. Open Cup Adjudication and Discipline Panel conducted a hearing and reviewed the available evidence.

The investigation included looking at the available video, as well as interviewing the match referee, Diomande, the accused Portland player, and other players from both sides.

The USSF said in a statement that the player "strongly denies using a racial epithet."

"After reviewing all of the available information, the Panel found no other individual that was able to confirm they heard the alleged use of the racial epithet," the USSF said in a statement.

It added: "While in no way diminishing the serious allegation, the Panel also took into consideration that the alleged incident occurred while multiple speakers spoke at the same time in multiple languages during a tense situation, which could allow one individual to misunderstand another individual."

The Timbers said the investigation showed "there is no corroboration that the incident occurred."

"It is our strong belief that the alleged incident in the U.S. Open Cup match as depicted by the opposing player simply did not happen," a club statement said.

Diomande then suggested he was not happy with the decision in a new Instagram message posted on Thursday night.

"They will say [you're] a liar and it never happened 3 weeks ago. They will say no perfect camera angle, lips reading or any other evidence to prove [you're] right," he wrote. "They will tell you a word that is nothing in this world can accept at all.

"I told them only me and him knows what's been said but at the end of the day I will always forgive but never forget what happened that night!"

In their written decision, the U.S. Open Cup Adjudication and Discipline Panel explained, "this is a case of a dispute over what was said between players on the playing field, amidst noise, confusion and multiple speakers speaking at once and in at least two languages. The match official did not hear the statement in question and did not issue a caution based on the incident, nor did any other player in the vicinity come forward to confirm they heard the alleged statement...

"Given the possibility that it is always possible to mishear or misunderstand another individual in a tense situation, the Panel concluded it does not have a basis to value the credibility of one player over another in this matter."

Adama Diomande Jayne Kamin-Oncea-USA TODAY Sports

Diomande had words with a number of Timbers players in the 90th minute after a hard foul on his teammate Carlos Vela. They had to be separated and Diomande then attempted to state his case to the referee while Timbers players tried to calm him down.

Then a few minutes later, the LAFC man squared up with a number of Timbers players again after being the target of a late tackle.

Diomande, a 28-year-old Norway international who joined LAFC in May, explained his actions after the game.

"Today was the first time in my professional career that I was called the 'N' word on the field," Diomande wrote last month. "They will say sorry to me after the game and please let it go, but If I don't say anything racism will just continue to grow.

"No matter which country, color, religion or which language [you're] speaking we all are human being and we should respect each other no matter what! #saynotoracism"