The Gunners were forced to replace Saka, 20, at halftime after being punched from behind by the Crystal Palace man as he fielded a volley.
Referee Mike Dean had previously whistled for an offense in the penalty area and had chosen to reserve only McArthur, who moments earlier had escaped without a yellow card for a cynical foul.
Speaking on Sky Sports, Arteta said: “We had to take him off because he couldn’t continue, he was in great pain.
“I saw the action and can’t believe how [McArthur] continued in the field. “
When asked if it deserved a red card, he replied, “Absolutely. “
Arteta called on VAR to take a more proactive role in protecting players from the kind of challenge that hurt Saka.
He told reporters: “If we want to detect things that are really relevant in a game and can change a football game, then they have to be looked at.
“This situation does not only affect them, but we have to take the player out because of the action, so it affects him in two different ways. It’s not correct.
” You [need to] make a clear decision, when it’s so clear and obvious right away and they have to play with ten men.
The Gunners now face a nervous wait to see if Saka will be fit for Friday’s clash with Aston Villa.
Arteta added: “Obviously he couldn’t continue and he’s a pretty tough boy and he wants to keep playing, and he couldn’t continue.
“We have a quick turnaround for the next game so we’ll see how he plays out. “
Liverpool legend Carragher noted: “He had a few challenges before that, James McArthur, where you said, ‘Could be a yellow’.
“But it’s so strange. At first you think it’s the one where they don’t see the player, focus on the ball and the player comes out of nowhere.
” Most [Saka]is actually right in front of him. There’s no way he can’t see it as he tries to steal it.
“The referee has just whistled for a handball in the area. He got away with it. There is no doubt that Palace or McArthur would have no qualms if it was a red card.