His activity in passing lines is huge for the team right now.
He's much better defensively than I expected he'd be given his lack of height and length. He's been Tony Allen-esque this season.
With that said, he's also been a borderline disaster offensively in every situation other than fast breaks (and he's not even particularly great in that situation).
He's played starter level defense and then some, but the Celts need him to become at least a serviceable offensive player.