I have been saying it since they signed Miles, he will not make this team. Miles has to prove that he can still play, that he has matured, that he is willing to play defense first and offense second, that he still has his athleticism since that is such an important component of his game, and that his knee will withstand a year's worth of NBA stress and punishment.
When it all comes down to it, that's an awful lot to prove definitively and from what I saw last night, he hasn't proven much of anything yet. He's overweight, he's still not in great shape, he's clearly not close athletically to where he once was, and doctor's exams at the end of the preseason will tell a significant story as to whether his knee will last or not.
With a non-guaranteed contract, it's fairly obvious to me, and has been for some time, that he will not be making this team.