It’s always been obvious that William Saliba has a ton of talent, but there was something about his game that Mikel Arteta didn’t trust just now.
It’s possible that he just didn’t feel he could trust such a young centre back when a mistake can be the difference between winning and losing.
At least his loan spell with Nice will give him a chance to make those mistakes and gain more experience, and he’s just seen how ruthless opposition forwards can be:
Pictures from Eleven Sports
In a way you can credit Saliba because he’s trying to build from the back instead of booting the ball away, but it’s a poor pass and Martin Terrier has shown him no mercy by picking up the loose ball and thumping it home.