I saw some clips (and tried to link them here but they didn't work) of him in situations that involved literally ANY physical contact. He cant set a screen, like he deliberately avoids contact with the man he is screening, in the paint or even the high post, defenders that were much shooter than him were easily able to push him several feet back and his rebounding instincts just don't exist. Guys he should easily board over him would zip around him and out jump him for the ball as he just stood flat footed hoping the ball would fall to him.
I don't think he will ever be a rotation player. He's going to be an end of the bench novelty that the crowd will get a kick out of when games get out of hand.