Manchester City reached the FA Cup semi-finals with a dramatic comeback win against Swansea, but the absence of the Video Assistant Referee was one of the big talking points after the match.
Having trailed 2-0 at half-time, City pulled a goal back through Bernardo Silva and then levelled from the penalty spot after Sergio Aguero's penalty deflected in off goalkeeper Kristoffer Nordfeldt.
Swansea were aggrieved at the awarding of the penalty as Cameron Carter-Vickers appeared to win the ball rather than foul Raheem Sterling. And there was further controversy with City's winner as Aguero headed in from an offside position in the 88th minute.
VAR is in use during the FA Cup, but only at Premier League grounds, meaning neither decision was able to be reviewed.
We look back at the incidents and how they would have been impacted if VAR was in use, and what was said about the decisions and lack of VAR…
Would VAR have reversed the decisions?
It's impossible to say for certain with City's penalty call, but it would have overturned the winner, which Aguero clearly scored from an offside position.
City's penalty was awarded when Sterling nudged the ball past Carter-Vickers, who slid and appeared to win the ball as Sterling went to ground.
Referee Andre Marriner pointed to the spot and, after Swansea players protested the decisions, Aguero converted the penalty, albeit with some good fortune as it hit goalkeeper Nordfeldt and went into the net.
Aguero then scored the winner as he stooped to head in from Bernardo Silva's cross.
While it was a fine finish from Aguero, replays show he was in an offside position and if VAR was in use then the goal should have been ruled out.
Why was VAR not in use?
FA rules this season state that VAR must be used, but only at games being held at Premier League stadiums.
Swansea were in the Premier League between 2011-2018 and their stadium is equipped for VAR. However, it was not used for this match.
A Swansea spokesman told Press Association Sport: "We are in the dark ourselves over the non-use of VAR here and that it would only be used in Premier League stadiums.
"That seems a bit strange considering we were there for seven years and all the technology is placed here to accommodate it."
There was also VAR controversy in the fourth round as Millwall scored against Everton and the goal appeared to deflect into the net off Jake Cooper's arm. Again, as the match wasn't at a Premier League ground, VAR was not in use.
Former top-flight referee Keith Hackett wrote in the Daily Telegraph after the match: "It was an amazing decision to deploy the video assistant referee on a selective basis in the FA Cup this season.
"One can only assume that the Football Association - and the Professional Game Match Officials Limited - are continuing their experimentation. Even so, to have it in some games and not others is unfair, and that was demonstrated over the weekend."
Everton manager Marco Silva also said the VAR rules "do not make sense".
"You have to do it for all the games. You have to be fair. If the competition has VAR for some stadiums then it has to have it in all."
What was the reaction?
While Swansea manager Graham Potter preferred to focus on his team's performance rather than the controversial calls, City boss Pep Guardiola apologised to Swansea.
"You have to ask the authorities why VAR is not here. All around it is there, but here it is not.
"If it's not a penalty and it's also offside, I am sorry. I don't like to win games when decisions are wrong. It's not easy."
Pundits and former players, as well as others on social media, were unanimous in their disagreement with the lack of VAR...