It was clear to me that Junior was taking his man to the hole and being successful. Then yank, he is gone. Not a defensive guru, but is he blowing it on defense? Not worried about this game as beating ND on the road is tough, especially with ticky tack fouls and we play aggressive.
I think his defense is pretty good, he generally stays in front of his man on the perimeter. He kept getting caught guarding bigger people on the switches last night, and he has no hope of stopping those kind of guys where Buycks at least has a chance.
Once they went zone and negated his penetrating, he is much less useful on the floor.
As others have said on this board, it appears that is Buzz's scheme, that the guards help to double down on the bigs. That can leave the other team guards open for wide looks. Sometimes it works, and many times it doesn't.