Police are investigating after Swansea striker Morgan Whittaker suffered "vile racist abuse" following Saturday's game against Derby.
The 20-year-old was targeted after scoring against his former club and becomes the fourth Swans player to be racially abused on social media since February.
Yan Dhanda, Ben Cabango and Jamal Lowe have all suffered racial abuse, and the latest incident happened as English football was part of a mass social media boycott against sustained and spiralling online abuse.
"Swansea City is saddened, angry and appalled by vile racist abuse received by Morgan Whittaker via social media following Saturday's game against Derby County," read a statement from the Sky Bet Championship club.
"The abuse in question has been reported to South Wales Police and the club is assisting them in their investigation.
"The fact that this has happened across a period where clubs, players and stakeholders have come together for a boycott of social media for this very reason, again shows just how much work still needs to be done.
"Morgan is sadly the fourth Swansea City player to suffer such abhorrent and disgraceful abuse online since February – a damning indictment on the world we live in.
"As a club we will continue to strive for change, urging social media companies to take strong action and implement real change on their platforms that will enable its users to open their accounts and not have to worry about what they might find.
"Chief executive Julian Winter recently wrote to both Twitter and Facebook, the latter replying with examples of how they try to combat online abuse. But with vile incidents appearing on a daily basis, stronger action is clearly required.
"Morgan has the full and unwavering support of everyone at Swansea City, and our message remains clear. Enough is enough."
A statement from SWP read: "South Wales Police is investigating the origin of racially motivated social media posts aimed at a Swansea City footballer following the club's match against Derby County this weekend.
"South Wales Police has designated football liaison officers who work with clubs throughout the force area to help prevent and deter crime and anti-social behaviour.
"Tackling hate crime has always been a priority for South Wales Police – this behaviour is something that will not be tolerated in our community.
"The force takes hate crime seriously and works closely with those involved in football to raise awareness of hate crime amongst players and supporters."
Swansea took a stand against online abuse and discrimination on April 8 by not posting any social media content for seven days.
The Welsh club called for social media platforms to introduce tougher policing and punishments for those found guilty of sending online abuse.
Birmingham and Rangers quickly supported Swansea's stance of a seven-day social media boycott, and on Friday much of the sporting world followed suit.
The boycott – which started at 3pm on Friday and runs until 11.59pm on Monday – saw a coalition of football's largest governing bodies and organisations, including the Football Association, Premier League and EFL, among those to go silent on social media in a show of solidarity against online abuse.
European governing body UEFA also joined in, as well as Scottish and Irish football, England Rugby, Scottish Rugby, British Cycling, the Rugby Football League, British Horseracing, the England and Wales Cricket Board, the Lawn Tennis Association, International Tennis Federation and others.
Prince William, who is president of the FA, and seven-time Formula One world champion Sir Lewis Hamilton also pledged their support by joining the boycott.
