Porto striker Moussa Marega was trying to go about his business last Sunday when he was subjected to racist abuse from fans of Portuguese club Vitoria Guimaraes. After the Mali international scored what turned out to be the winning goal, he was bombarded with monkey chants whenever he went near the ball. Understandably, Marega refused to keep playing in those conditions, and decided to walk off.

Here's what should have happened next: Marega is met with an outpouring of love and support. Everyone – from his teammates and manager, to Porto's mascot, Draco the Dragon – immediately surrounds him in a ring of solidarity, walking him off the pitch to a chorus of cheers that drown out the abuse. A nation humiliated, Marega never has to buy another pastel de nata, as each perpetrator is found and banned from being anywhere within a single radial mile of a football ever again.

Here's what actually happened next: Marega – alone, isolated, made to look like he was insane – had to fight his way off the pitch, fending away his own teammates, who were trying to force the 28-year-old to stay on the pitch and spend the next 30 minutes enduring a public mocking for being black, rather than allowing him to walk towards dignity. Marega stayed strong and left – but not before the final humiliation: he was given a yellow card for his behaviour.

You could replace the names Marega, Porto and Vitoria with Balotelli, Brescia and Verona, and you'd have an almost identical incident from three months ago during a Serie A match in Italy. Only, in that instance, Balotelli eventually decided to stay on, without a single player offering to walk off with him.

Footage of both incidents quickly spread across Football Twitter, with most fans, players and pundits angry that each player's teammates chose not to stand with them. Responding to the Marega incident, anti-racism campaign group Kick It Out said in a statement: "The blatant disregard for protocol is unacceptable, and players should be united and walk off together in their condemnation of racism, instead of this."

Watching the clip, I felt heartbroken for Marega, then embarrassed for Porto fans. That embarrassment was soon replaced by a sense of panic: what if the team I supported behaved like that? After all, considering recent events, it's only a matter of time before a black player walks out of a Premier League match.

In early December, a Manchester City fan was arrested after allegedly making monkey gestures towards Manchester United players. Two weeks later, Tottenham were forced to make three stadium announcements to remind fans that racism was bad, after Chelsea defender Antonio Rudiger and Tottenham forward Son Heung-Min were both reported to have suffered racist abuse. A month earlier, an FA Cup match was abandoned between Haringey and Yeovil when the Haringey players walked off in solidarity with their goalkeeper, Valery Douglas Pajetat, after he was spat at and hit by an object.

The day after the Marega incident, I reached out to every Premier League club to understand what they as a team would do if one of their players decided to walk off after receiving racist abuse, as Marega and Balotelli did. The quality of the responses was mixed, with some clubs demonstrating a coherent, club-wide approach to dealing with the issue, and others showing very little interest in engaging with the topic at all. Four days later, despite multiple opportunities to do so, a few clubs simply haven't responded.

Top of the League – Liverpool and Arsenal

Liverpool were first to respond, with what turned out to be the strongest answer: "If one player walked off, everyone would walk off." Nice and simple, like their journey to the title.

Arsenal were a close second. After an initial statement about being "fully supportive of any of our players or staff if they were the victims of racist abuse", I received a call from a club spokesman who wanted to explain in more detail the comprehensive steps they were taking across all their teams – men and women of all age groups – to make sure players knew that they would be fully empowered in that situation, and that the team would stand by them. The club is certain that what happened to Marega and Balotelli would not happen at Arsenal.

Strong contenders – Manchester United, Tottenham, Newcastle, Southampton

Manchester United have a lot of faith in the effectiveness of the Premier League's racism protocols – a set of steps referees are required to take if they think a player is being racially abused. The steps rise from making a stadium announcement asking the crowd to stop, to taking the players off the pitch for a period of time, and finally abandoning the match completely. United believe that if these protocols are followed properly, "players won't be left in the position of having to decide for themselves how to respond during a game". Importantly, it was clear that the club is not a passive actor in the response, only relying on the referee, but that players and officials are taking active steps behind the scenes to make sure the right thing is done in their matches.

Tottenham took a similar approach: "We hope this circumstance would never arise due to stadium management of issues and protocols in place. If it did, then of course the player would have our full backing if they have been racially abused." In a follow-up conversation, the club clarified that no player would be encouraged to stay on if they wanted to walk off.

As with Spurs, Southampton made clear that encouraging players to stay on when they had made the decision to walk off would not happen. "As a club, we would support a player's decision wholeheartedly."

Newcastle declined to comment on the record, which was surprising, because in my conversations with them they were extremely engaging and thoughtful on the issue, and it was clear that it was something they took very seriously.

'Racism is a bad thing' statements – Norwich, Everton, Leicester

Sitting at mid table are the more standard, general statements.

Norwich: "Generally speaking, as a club, we'll of course support and stand by our players through any form of discrimination.

"I think it's difficult for us to publicly comment on players walking off the field of play, as each and every situation in that particular instance could be impacted by a range of differing factors."

Everton: "Everton strongly condemns any form of racism. Racism has no place within our stadium, our Club, our community or our game. The Club would fully support any players or staff if they were the victims of racist abuse of any kind."

Leicester: "Leicester City Football Club is committed to equality and to helping eliminate racism and all forms of discrimination from football. Abuse of our personnel will not be tolerated and the Club will seek the strongest possible sanctions for those responsible. Any players or staff that are the victims of abuse will be offered the Club's full support."

No comment – Crystal Palace, Sheffield United and Wolves

Crystal Palace decided not to respond, as the club does not have an "official position on this."

In my conversation with Sheffield United, they were adamant that they did not want to engage with us on this discussion at all.

Wolves simply declined to comment.

At the time of publication, despite several attempts to reach them, we had not received any responses from Chelsea, Watford, Burnley, Manchester City, Brighton, Aston Villa or West Ham. This article will be updated with their comments if and when they arrive.

If you are in any way concerned by your club's response, I strongly recommend getting in touch with them. There is no single way to handle such a delicate issue, but too many are clearly banking on young footballers to respond in the heat of the moment, rather than coming up with comprehensive club-wide strategies on how to do deal with a situation that is creeping dangerously towards the norm.