Arsenal have lost their appeal against the red card shown to Max Dowman during their English League Cup defeat away to Fleetwood Town on Thursday.
The young midfielder was dismissed by referee Michael Salisbury in the match at Highbury Stadium, which Fleetwood won to advance in the competition.
The club's challenge against the sending-off has been rejected, meaning Dowman will serve the mandatory suspension.
Arsenal's exit from the League Cup came as a surprise, with the Premier League side falling to lower-league opposition.
