Everton goalkeeper Jordan Pickford will not face retrospective action over his challenge on Virgil van Dijk in Saturday’s Merseyside derby.

The Liverpool defender suffered cruciate ligament damage when he was caught by Pickford in the first half.

The injury is likely to keep him out for at least six months and potentially the rest of the season.

The FA does have the power to intervene even if a decision is seen, but this is only used in exceptionally rare circumstances.

Evidently, these circumstances do not apply on this occasion.

Liverpool manager Jurgen Klopp has refused to put a timescale on Van Dijk’s recovery but says he will be out for a “pretty long time”, with a date for surgery yet to be arranged.

“A few things are clear, so he now will be out for a while, that’s clear,” said Klopp. “I expected it pretty much on Saturday immediately after the game , especially when I saw the challenge back. I saw it the first time only from the bench, and when I saw it back it was pretty clear that he will be out for a long time.

“So we feel now in this moment extremely, extremely for him because most of us have been in a similar situation and we know that these situations are absolutely rubbish.

“You don’t need it. You don’t need it but you have to get over it and Virgil will get over it, 100%, and today is already the first day, if you want, of the recovery.”

Klopp also said he had been in touch with the Dutchman, who is doing “OK”, with the club ready to do everything it can to support the defender during his rehabilitation.

How did Van Dijk get injured?

Fabinho looped a cross to the far post which Van Dijk was about to try to control when Pickford came flying out feet-first and trapped the defender’s right leg in a scissor-like movement. Van Dijk was immediately in pain.

As Van Dijk was being treated, the VAR noted it was checking for a ‘possible penalty’. In the end, it could not have been a penalty because Van Dijk was offside. Referee Michael Oliver gave a free-kick to Everton, Van Dijk left the pitch and the game carried on.

Confusion over potential punishment

Initially there was confusion over how the Pickford challenge had been assessed.

There was a theory no action could be taken because of the offside decision. However, while that would have prevented a penalty being awarded, it would not have stopped Pickford being shown a red card.

Evidently, neither Oliver nor the VAR saw fit to impose such a punishment.

VAR can only intervene for offences they deem to be worthy of a red card. If, for instance, they felt Pickford had made a genuine attempt to play the ball – and Oliver had not seen the incident at all – it would only have been a yellow card.

However, they could also have asked Oliver to view the incident again on the pitch-side monitor.

FA cannot re-referee incidents

The Football Association still has the power to take retrospective action over match incidents that are not seen by the officials, including by VAR. However, they are not supposed to re-referee situations, which has caused controversy in the past.

A prime example of this was in March 2013 when Wigan’s Callum McManaman caught Newcastle’s Massadio Haidara with an awful challenge at the DW Stadium.

Haidara was stretchered off but because one of the officials saw the tackle, no further action could be taken, even though most observers felt it was worthy of a red card.

Newcastle managing director Derek Llambias said afterwards that the FA’s disciplinary process was “not fit for purpose”.

In theory, no incidents should be missed by VAR. However, as was proved in the first game of ‘Project Restart’ when Sheffield United were denied a goal at Aston Villa after VAR failed to spot that goalline technology had failed, sometimes even the most basic of errors can occur.