I think there is a different between "fights" and "proper aggression" that people get mixed up here.
For instance, if Kassian isn't fighting... HE DOESN'T DO ****. Heck, he doesn't even do anything when we look intimidated.
Neil too, nowadays, he'll throw a big hit now and again but he doesn't step up to the other team's face and agitate them when we needed him most.
Carkner would always respond whenever anyone even looked at our players funny. That's why I loved him.
That's why Boro will be loved here. He plays with consistent physicality all the time, not just when he is squaring off.