"It's honestly embarrassing that some Man City fans think it's OK for their players to sing about fans being beat up", one Liverpool fan tweeted, while many more responded saying the video was "classless", "unprofessional" or "naive".
So, what happens if City are banned from next season's Champions League?
Just a day after making it back-to-back titles after pipping Liverpool to top spot on the final day of the season, a New York Times report revealed that UEFA are looking to ban City from next season's Champions League following an investigation.
It is unclear which players and staff - if any - are joining in the song, which recalls Liverpool's defeat in last year's Champions League final in Kiev.
A City spokesperson said: "The song in question, which has been a regular chant during the 2018-19 season, refers to the 2018 UEFA Champions League final in Kiev".
What is financial fair play?
According to Der Spiegel in November, City had breached FFP rules by €188million in that year.
"If what has been written about Manchester City is true, there might be a serious problem", Leterme said.
Chief investigator Yves Leterme will pass any recommendation on to UEFA's adjudicatory chamber, which would have to decide whether it agreed any proposed punishment was suitable.
But it is understood UEFA would deem a season-long ban to be suitable punishment if City are found guilty.
Should City - whose current squad has been amassed at a cost believed to be close to £1 billion - face a ban it is unknown whether it could be enforced in time for next season's competition, due to the likelihood of an appeal and, should that fail, a later appeal to the Court of Arbitration for Sport.
What could it mean for Arsenal?
The club have already been punished for violating FFP, striking an agreement in 2014 that saw them fined rather than banned from the Champions League for inflated sponsorship deals with companies linked to the club or their ownership.
But, as previously mentioned, it is unlikely the case will be settled that quickly.