Arteta was enraged during his side’s defeat at Old Trafford when Gabriel Martinelli had a goal disallowed when Martin Odegaard was adjudged to have committed a foul on Christian Eriksen in the build-up to the goal.
“It’s a lack of consistency,” Arteta told Sky Sports. “What is soft? Last week, they [Aston Villa] got a goal when there’s a foul on Aaron [Ramsdale], but it’s soft and it’s not a foul.
“Then there’s a penalty on Bukayo [Saka, by Tyrone Mings] but it’s soft and not a penalty. Today this is a foul. There were some strong tackles and no yellow cards because the threshold is low because it’s a big game. It’s really difficult to accept.”