Detectives said officers are working with Manchester City Football club to identify who threw a coin at Rio Ferdinand.
Charges of those arrested included a racially aggravated public order, pitch encroachment, public order, breach of a football banning order and being drunk and disorderly.
Chief Inspector Steve Howard said: "Despite fierce rivalry and high tension there was no major disorder. However, we will continue to investigate the coin throwing incident and are determined to work with the club to bring the perpetrator to justice."
More top news
Trains on some of the UK's busiest rail routes will be "significantly" hit by a rail workers' strike from tonight.
A new report stresses the "critical" need for emergency services to adopt text and social media alerts.
The smuggler turned hero - made famous by Harrison Ford - will star in his own stand-alone film, Disney says.