Everton have reportedly asked the Premier League's refereeing body why Joel Matip’s challenge on Anthony Gordon in the Merseyside derby was not reviewed further.
Everton felt they should have been awarded a penalty when Gordon went over in the box after contact from Matip.
The game was goalless at that stage, but Liverpool scored through Andy Robertson eight minutes later and wrapped up a 2-0 win thanks to a late goal from Divock Origi.
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According to Sky Sports, Everton want an explanation from the Professional Game Match Officials Limited (PGMOL) why the VAR check for the penalty claim was so quick.
Referee Stuart Attwell waved away the protests from Everton players and VAR Darren England did not deem it necessary to intervene.
The check from the VAR did not even constitute a break in play.
Everton received an apology from the PGMOL earlier this season after they were denied a penalty when Manchester City midfielder Rodri appeared to handle the ball in the box.
The defeat to Liverpool left Everton in the Premier League relegation zone with six games of the season to go.
Frank Lampard's side are two points from safety, although they have a game on Burnley, who are one place above them.
Lampard said after the Merseyside derby that if an Everton player had made the same challenge as Matip then it would have been a penalty.
"It was a penalty in the second half. I don't think you get them here. I think if that is Mo Salah at the other end, he gets the penalty.

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"I am not trying to create conflict there, I just think it is the reality of football sometimes. Maybe I have played for clubs sometimes at the top reaches of the league, with the crowd behind them, you get more than you don't.
"The second one on Anthony is a foul. It is a clear foul. But you don't get them here."
Gordon had been involved in another incident earlier in the game when he was booked for diving in the box.
Former Liverpool defender Jamie Carragher thinks that may have played a part in the decision not to award a penalty in the second half.
"He's got to be careful Anthony Gordon, he's a local player and I know some of his friends and family," Carragher said.
"He's a great player and lad, one of the best on the pitch today. He caused Liverpool massive problems, it's not the first one in the first half, he's just got to be careful of that. It'll definitely be in referees' heads and maybe he hasn't got what he's deserved because of a few incidents in three or four other games. But that said, it's a stonewall penalty."
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