Everton goalkeeper Jordan Pickford will face no further action over his challenge on Virgil Van Dijk but has been targeted on social media in messages that are being investigated by Merseyside Police.
The PA news agency understands the England international will escape punishment for his tackle during Saturday's 2-2 derby draw that left Van Dijk needing knee surgery because the incident was seen by the match officials.
Under the Football Association's disciplinary rules, retrospective action can be taken if an incident was either not seen at the time or when it was reviewed by VAR.
Van Dijk was forced from the field after the pair collided during a Reds' attack, with Pickford desperately trying to block the defender's passage to goal.
The incident was reviewed by VAR official David Coote, with the Holland international adjudged to have been offside before he was caught by the keeper, although it was later suggested the actual challenge had not been re-examined and referee Michael Oliver was not asked to take a second look.
However, former referee Dermot Gallagher has insisted Pickford should have been dismissed.
Gallagher told Sky Sports News: "There are three steps: is it offside? Is it a penalty? Is there further sanction?
"Is it a penalty? Well, it is a penalty, so you have got to go back and check if it's offside. They check the offside, it is offside, so that negates the penalty, so I think what they've done, they've gone back from step two to step one.
"Obviously step one eliminates step two and it got overlooked to go to step three, which it should have done and we all know it should have been a red card.
"It was just a human error and all we can do is apologise for it and there's nothing more you can say."
Liverpool have confirmed that Van Dijk suffered anterior cruciate ligament damage in the incident and is expected to be sidelined for several months as a result of surgery, although he is yet to be ruled out for the remainder of the season.
Liverpool and the club's fans were incensed by the incident and the lack of action taken against Pickford, while Richarlison was later sent off for a bad challenge on Thiago Alcantara.
Merseyside Police confirmed they are investigating offensive messages sent on Twitter targeting two Toffees players, believed to be Pickford and Richarlison.
A spokesperson said: "We are currently investigating a number of offensive Tweets made in relation to two Everton footballers.
"The language used in the Tweets is totally unacceptable and we are taking the reports extremely seriously.
"Those who use the internet to target others, and who commit criminal offences such as making threats or committing a hate crime in doing so, are not beyond the law.
"Detectives are making enquiries to identify the individuals who posted the Tweets and, where we identify offences, we will take action to bring those responsible to justice."
