Fulham say they will take the “strongest possible action” after forward Aboubakar Kamara was racially abused on social media following Saturday’s win over Huddersfield.
Kamara, 23, missed a penalty after refusing to give designated penalty-taker Aleksandar Mitrovic the ball.
He was abused online after the Premier League match, which Fulham won 1-0 thanks to a late Mitrovic goal.
In a statement, Fulham described the comments as “damaging and hurtful”.
“As a club that prides itself on our respect and civility, we condemn anyone who may be associated with this repulsive activity,” said a club spokesperson.
“This is not representative in the least of genuine Fulham supporters, many of whom have posted messages of support and encouragement to the player.
“The club will provide all necessary support to Aboubakar and will take the strongest possible action against those identified and responsible for these posts.”
After the game, Fulham manager Claudio Ranieri said he “wanted to kill” Kamara and accused him of disrespecting everyone at the club.
But Mitrovic defended the Frenchman, saying: “He’s a striker; he’s hungry for goals as well. He scored his last penalty.
“It’s normal. He’s young. These kind of things can happen. You need to take care of each other.”