LONDON (REUTERS) - The Premier League's VAR system was back in the spotlight at Chelsea on Saturday (Feb 22) when officials reportedly said they had made a mistake by not recommending a red card for Tottenham Hotspur midfielder Giovani Lo Celso in the Premier League game.
The Argentine appeared to stamp on Chelsea captain Cesar Azpilicueta's shin as Spurs lost 2-1 in a battle for fourth place. But after a check for possible violent conduct by the video-assisted officials, Lo Celso escaped without censure.
Referee Michael Oliver, who did not even brandish a yellow card for the tackle, did not view a pitchside monitor.
Chelsea manager Frank Lampard, who on Monday criticised a VAR decision not to send off Manchester United's England defender Harry Maguire for planting his foot in the groin of Chelsea striker Michy Batshuayi, held his head in disbelief.
As the game continued, a television presenter said officials at the VAR offices in Stockley Park, a few miles away from Stamford Bridge in West London, had admitted their error.
"We have been speaking to Stockley Park who have admitted they got the decision wrong and Lo Celso should have been sent off," Jake Humphrey, who works for BT Sport, said on Twitter.
After the game, Lampard said the incident represented just "another huge question mark" for VAR which was introduced to the Premier League this season.
"I was just waiting for the red card to be shown," he said. "It's just not good enough. Saying afterwards they made a mistake is not good enough. They had... a couple of minutes they took to try and get it right.
"The whole world saw that. I hate to stand here and call (for) a red card, but that is a leg breaker.
"I am not saying anything about the referee on the spot, because it is hard there, but it is not good enough." Azpilicueta was equally baffled.
"I'm not a player that likes to be on the floor because I'm tough but it was not my fault because it was a clear stamp on my shin, I felt it straight away," he said.
"Obviously everybody makes mistakes but when you have a lot of replays it could be easier." Former Arsenal manager Arsene Wenger, summarising for BeIN Sports, said it should have been an easy decision.
"It was a straight red card. I don't even see why they needed three minutes to make the decision," he said.
Premier League clubs will consider making changes to the way VAR reviews are used from next season, including the scant use by on-field referees of pitch-side monitors to review incidents themselves, the league's chief executive Richard Masters said earlier this month.
Most of the controversy about the system has related to close offside calls often involving goals that are ruled out when an attacker is a few millimetres ahead of a defender.