The thing is, in order to play consistently at his highest level of defense, he'd have to get down to about 32 mpg, and the sixers just can't afford that. He proved last year that he has the ability to shut people down in pivotal stretches, but with the way he plays on offense, how much he sprints, he just can't do it for long stretches. Also, I think he has lost a half-step in lateral quickness.