The striker, who has hit 14 goals in the Premier League this season, was sent off in Saturday’s 1-1 draw at Crystal Palace.
It means he will the miss next three games, including when the Blades visit the Emirates on Saturday.
The 30-year-old was originally shown a yellow card following his tackle on Palace’s Max Meyler but VAR intervened and upgraded it to a straight red.
Speaking to Match of the Day, Arsenal manager Mike Arteta, said: "I saw that he caught the player.
“Obviously there is no intention to make such a foul or injure the player but VAR made the decision and we have to accept it.
“To lose him for three games is a massive blow for the team but we have other players.
“We will trust them and we will put them on and we will find solutions."