William Saliba became the third Arsenal player to be sent off this season after being shown a red against Bournemouth.
The French defender pulled down Cherries striker Evanilason following a loose back pass from Leandro Trossard after 28 minutes.
Saliba was initially booked for the challenge. However, Rob Jones was sent for an on field review and overturned it to a red.
Former Arsenal striker Alan Smith, who was on co-commentary for Sky Sports said: 'It is an instinctive challenge, he is a quick lad, but would he have had the pace to get back?'
'He may have got round on the cover but he had a lot of ground to cover, he really did'