Don’t want to turn this into a miller thread but do want to say it seems extremely premature and arguable incorrect to say miller is poised to be a great defensive player. Either way, definitely not in the stratosphere of McConnel
The only other player who is as impactful as Caleb on defense, at the moment, is Paul. They are different players and have different impacts. But both are huge components of the defense when it's at it's best. And I would argue that neither one would be quite as good at what they do without the other because I think they are complimentary in their skill sets - they appear to me to make each other better.
Miller is a first year player, so he's obviously not at the level of the other upper-classmen at defense. However, he does, to me, demonstrate the qualities necessary for a great defender. I said "poised", but perhaps I should instead say he demonstrates a lot of potential. That potential may be realized. Or it may not. Only time will tell.
He has energy, but he also has lateral quickness and acceleration. Defending the ball, he does well enough now that the coaching staff inserts him into the defense to guard pretty good point players from other teams. And he will only get better at that as they work on his footwork and technique in general.
What remains to be seen is if he will develop the timing (aka next pass anticipation - CM is great at this), cue-recognition (aka anticipation of where the ball will go
after the next pass - PM is great at this), and discipline and other team-defending skills that he'll need to be truly great and well-rounded defender.
Again, only time will tell. But I see definite signs of potential. Hope he fulfills that potential.