Arsenal manager Unai Emery said he wanted his players 'to be angry' after Pierre-Emerick Aubameyang expressed discontent at being substituted during a poor display at St James' Park.
Aubameyang's performance on the Arsenal left underlined the problems Unai Emery is having in deploying the Gabon international and Alexandre Lacazette together.
But that offered no excuse for the former's poor delivery and control. Yet he still made it clear he did not accept being removed on 68 minutes.
Emery said of the player's reaction: 'It is normal. I want players when I change those on the field, and they are not in the first 11, to be angry... with ambition to play and help the team and to stay on the pitch. For me it is a normal situation.'
Aaron Ramsey also left the field early, after 80 minutes.
Emery said of him: 'He played with (the Wales) national team too much and he asked to change.. it was not a big problem but he was tired. I think no problem.'