I've been at every game so I think I qualify on that front.
He's clearly not ready physically, nobody can dispute that, but watching Martinelli trying to guard the 7+footer from DePaul (who's also a freshman by the way) made my stomach turn. He's practicing against a B1G quality big man every day in Page. He gets 5 fouls, so he can at least cover a few minutes and prevent some layups when Page is in foul trouble. He can handle the ball, looked like he knew what to do with it when he got it.
We got lucky when Page, Singleton and Martinelli had four fouls but were able not to get a fifth. It's not a perfect solution -- again, no one is saying that it is. But last year's team would have been better down the stretch if KJ had gotten some minutes in the preseason, and worked out some of the growing pains (and no, I have no clue why he hasn't been better so far this year).
I see no downside to giving it a try in some of these pre-season games. If it doesn't work after a few test runs, then he hasn't blown his redshirt...