Everton boss David Moyes conceded James Tarkowski's tackle against Liverpool for which he escaped a red card was reckless but he defended his centre back on Friday after the player received online abuse and death threats following the clash.
During Liverpool's 1-0 win, Tarkowski won the ball in a challenge with Alexis Mac Allister but his studs-up follow-through caught the Argentine midfielder square on the calf.
Tarkowski was shown a yellow card with VAR not intervening and after much criticism, the referee's body (PGMOL) acknowledged that Tarkowski should have been dismissed for serious foul play.
"Look, it's not acceptable for anybody in any walk of life. But we have to hold our hand up and say, after looking at it again, that it could have been a sending off," Moyes told reporters.
"But I don't think that means you get abused online because of that. It's part of football.
"He made, which looked at the time I thought, a really good tackle. But looking at it again, I think it was a bit reckless."
Everton condemned the abuse directed at Tarkowski and said they are aware of threats made towards the 32-year-old and his family.
"The club is liaising with James and his wife Samantha, and stands ready to engage with the social media companies and assist the police with any potential investigation," Everton said in a statement.
The defeat by Liverpool was Everton's first in 10 league games and Moyes's side are 15th in the standings ahead of Saturday's home game against second-placed Arsenal.
Although Everton are 14 points clear of the relegation zone, Moyes is not taking Premier League survival for granted with eight games left.
"We have got a good points total. We are not mathematically safe yet, but it will be a tough topple for the sides in the relegation zone," he said.
"There is a lot to play for... There are a lot of players out of contract. We must keep the players' focus right, and keep their mentality."