Arsenal have stripped Pierre-Emerick Aubameyang of the club captaincy following a disciplinary breach last week.
Aubameyang was left out of the squad for Saturday's match against Southampton, and Arsenal confirmed their decision to remove the forward as captain on Tuesday.
The club also said Aubameyang will not be available for selection against West Ham on Wednesday.
"We expect all our players, particularly our captain, to work to the rules and standards we have all set and agreed," the club said in a statement.
"We are fully focused on tomorrow's match."
Arsenal manager Mikel Arteta is due to give a press conference this afternoon.