Police are investigating "threats" made on social media against Everton players Jordan Pickford and Richarlison following Saturday's Merseyside derby.
Threatening tweets were sent to Pickford after he injured Liverpool defender Virgil van Dijk in a tackle.
Brazilian forward Richarlison was also sent racist abuse after he was sent off for a challenge on Liverpool midfielder Thiago Alcantara, the BBC understands.
Police said the culprits "are not beyond the law" and would face justice.
A Merseyside Police spokesman said: "The language used in the tweets is totally unacceptable and we are taking the reports extremely seriously.