Mikel Arteta says Granit Xhaka 'overstepped' the line against Burnley on Sunday.
The Swiss midfielder was shown a straight red-card for grabbing Ashley Westwood's throat early in the second-half.
The Gunners eventually lost the game 1-0 after Pierre-Emerick Aubameyang scored an own goal.
Arteta's side are now 15th on the Premier League table following their fourth straight defeat at home.
And speaking after the game, Arteta said Xhaka had let his team down by getting sent-off.
