He's been sent off twice in his career, most recently in the 16/17 season.
This season, across all competitions, he has our third highest number of yellow cards, with 6. Rodri and Bernardo both have 8 - are we agonising over their discipline?
He gets targeted a lot by opponents, and often receives little protection from the refs. If he didn't stand up for himself he'd be bullied off the pitch.
He's emotional but he's not out of control. He thrives in matches that have a bit of bite to them.
I'm not saying he necessarily always makes the right decision, or there aren't occasionally individual incidents that warrant a concern in the moment that he needs to calm down.
But there's absolutely nothing to suggest he can't be trusted to keep his head as much as any of his teammates.