A few thoughts on this.
First, if we have an eight man rotation, it would not surprise me at all if Livers is not part of it, and if Poole or Watson fills that spot. Especially if Wagner is going to play some minutes at the 4, I can easily see Matthews shifting to the 4 and one of Poole or Watson taking minutes at the 3. Don't get me wrong--I think Livers is going to be a very, very good player in time, but he may not be as ready to step right in as is Poole coming off a year at LaLu, or Watson with a year in the system. We, as fans, tend to look at how people fit from the standpoint of traditional positions, and Livers certainly looks more like a 4 than anyone else we have. But Beilein has established that he does not look at things that way, and is more inclined to play his best/most ready players at the 2-4 spots than he is to shoehorn positional requirements into his rotation.
Second, if there is ever going to be a year where the rotation expands, this would be the one. One of the reasons Beilein constricts his rotation is that there are guys he simply doesn't want out of the lineup for more than a few minutes a game--Walton, Irvin, GR III, Stauskas, Burke, Novak, etc.--which leaves limited minutes remaining. I'm not sure who that is this year. It won't be Mo--bigs don't play that much (fatigue) and he gets into early and frequent foul trouble. It won't be Duncan or MAAR--they too get into early foul trouble, and neither is so much better than their replacements that you'd rather play them tired than others fresh.Maybe Matthews or Simmons, but I think that's unlikely too. That leaves extra minutes to fill...and a greater likelihood that they'll add to the rotation by making more situational substitutions.
Just my thoughts.