Arsenal assistant manager Albert Stuivenberg and goalkeeper Aaron Ramsdale criticised the "inconsistency" around referees going to the VAR pitchside monitor after they lost 2-1 to Manchester City on Saturday.
Martin Odegaard was brought down by Ederson in the box during the first half and while VAR did look at the incident, referee Stuart Atwell was told not to look at the screen as it was impossible to say definitively that Ederson didn't touch the ball.
Arsenal were awarded a corner instead of a penalty per Atwell's onfield decision.
"It is a penalty but I am looking for consistency," Stuivenberg -- standing in for Mikel Arteta, who tested positive for COVID-19 -- said.
"We have VAR in place so why not check yourself as a referee? That did not happen so it is disappointing."
Arsenal goalkeeper Ramsdale said: "I am basing it on both penalties -- the inconsistency of going to the screen, the referee might have ruled it out straight away when he looked at it.
"But it is the fact he went to look at it. Both in real time he said no penalty, but he only gets told to look at one. Theirs was soft but he gets told to look and has given it.
"I am at the other end of the pitch for our penalty shout. The goalkeeper comes out with his foot and he either catches him or the ball. The Bernardo one, he stood him up and it is got given.
"Penalties are penalties, but for us it is getting told to look at the screen."
Arsenal took an early lead through Bukayo Saka before Riyad Mahrez equalled the score with the penalty from the Xhaka incident. Arsenal were reduced to 10 men when Gabriel was sent off after receiving two yellow cards in two minutes.
City then scored a goal in added time through Rodri to secure their 11th win in a row.