Defensively, Zeller may lack some girth to defend bigger NBA centers and isn't the most imposing rim-protector (his 2 blocks per-40 minutes ranks 11th of the 15 centers in our top 100 rankings), but he's a very cerebral defender who understands positioning, both defending the ball and in help situations, as he does an excellent job drawing charges. He'll likely never be considered a game-changing defender at the center position, but his smarts and instincts should enable him to fit into a defensive scheme, where he has the potential to excel defending ball screens and making the proper rotations.
Perhaps the area we've noticed the most improvement in Zeller over the past year has been with his toughness and willingness to embrace contact in the paint. We noted before that he seemed to be a bit soft at times and was muscled around on occasion, but he showed more of a mean streak this year on both ends of the floor. After being a below average rebounder for three seasons, Zeller improved dramatically as a senior, showing great activity on the glass on both ends of the floor and grabbing 13.6 rebounds per-40, which was the highest of all centers in our top 100.
