Mikel Arteta was left livid after James McArthur avoided a red card after chopping down Bukayo Saka in Crystal Palace's draw at Arsenal.
McArthur made contact with the England international's right leg following a swipe after the latter had cleared the ball away from his own area.
The 34-year-old midfielder was only shown a yellow card by referee Mike Dean for the incident that left Saka clutching his calf on the floor towards the end of the first half of the 2-2 draw at the Emirates Stadium.
But Spanish boss Arteta claimed he could not believe the former Scotland international's caution was not upgraded to a red card, with Saka having to be substituted at half-time following the challenge.
'It was a red card (for McArthur), absolutely,' Arteta told Sky Sports. 'I cannot understand how he can stay on the field.
'We had to take (Saka) off because he could not continue. He was very sore in the area.
'When I look at the action I cannot understand how the (Palace) player can continue playing.'
Former Liverpool defender Jamie Carragher agreed with the ex-Everton midfielder, claiming VAR failed to overturn 'an obvious error'.
'There's no way McArthur can't see Saka there,' Carragher said.
'He's right in his eyeline, no one could have any qualms if McArthur was sent off there.
'It feels like it takes a lot for VAR to overturn a decision. It's an obvious error. It's a situation that should be overturned. He's just taken a swipe at him.'
Palace boss Patrick Vieira however channeled his inner Arsene Wenger, claiming he 'didn't see' the incident.
The former Gunners midfielder appeared crestfallen after failing to come away from north London with all three points.
Christian Benteke and Odsonne Edouard's goals put Palace on course for all three points after Pierre-Emerick Aubameyang's early opener.
But second-half substitute Alexandre Lacazette scored an equaliser for the hosts with the last kick of the game after adding speed and energy to the Gunners' attack following his introduction.
Arteta praised the 30-year-old striker - who has less than a year left on his deal - after the game, but admitted his frustration at his side conceding two 'cheap' goals.
'There is no doubt about (Lacazette's) commitment,' Arteta added. 'He transmitted a different belief and energy to the crowd.
'The way we conceded the two goals was too cheap. The team kept trying and we got the minimum we deserved.'
