Greater Manchester Police say they are aware of a racially abusive tweet about Arsenal striker Danny Welbeck.
The post came following Welbeck's winner for the Gunners against his former club Manchester United in an FA Cup quarter-final on Monday.
Police were informed of the abusive message when members of the public contacted them.
It follows an incident last month, in which Chelsea fans stopped a black man boarding a Paris metro train.
The Blues suspended five fans for an incident which occurred before Chelsea's Champions League game against Paris St-Germain.
Police are investigating reports of racist and abusive behaviour from Chelsea fans on a train from London to Manchester following their Capital One Cup win over Tottenham on Sunday, 1 March.