Arsenal's appeal against Pierre-Emerick Aubameyang's three-match ban for the red card he received in the draw at Crystal Palace has been unsuccessful.
Arsenal head coach Mikel Arteta said: "It's a big shame and a big loss for us.
"But unfortunately he mistimed the tackle, he made a decision and we have to accept it.
"He was very sad after the game, he was disappointed. It was an action that was completely accidental in my opinion.
"He's been superb under me. He's training well, scoring goals and has probably been the most important player in the team so to lose him is obviously really bad news for us."