Here are my thoughts:
Rozier
While Rozier is definitely still a bit raw (and has a long way to go) I honestly feel like he's the only guy on our roster right now who can do all of the below on a consistent basis:
* Create his own offense in ISO situations
* Shoot from three and from midrange (both spot up, and off the dribble)
* Get to the rim (and finish there)
* Score in transition
* Handle the ball
* Hold his own defensively
With a set of skills like that (and an NBA ready body) I think it's inevitable that he's going to earn himself some court time and make some impact in his rookie year.
Early on in the season I can see him earning spot minutes in situations such as:
* When we can't get open looks, and we need someone to attack the rim and collapse the D
* When our guys are looking lethargic and we need someone to come in and provide energy
* When we need points in a hurry, but can't afford to use IT for size/defensive reasons
As the season progresses I can see him earning a consistent role as an extra spark plug in 10-12 minutes off the bench due to his ability to create offense, and his ability to wreak havok (with his athleticism and high motor) on both ends of the court.
R.J. Hunter
I think that right now R.J. Hunter is a bit of a tweenter in that he doesn't have the strength to defender stronger wings (e.g. Joe Johnson) but also doesn't have the lateral mobility to defend quicker wings (e.g. Paul George). I think he may struggle defensively on some nights for that reason.
Offensively I feel Hunter is probably going to be limited to catch-and-shoot / shoot-off-screen situations, as I don't think he'll have the ability to create offense or get to to the basket against NBA talent.
However Hunter's biggest strength is his Basketball IQ, and as the season progresses I think he'll learn how to use his intelligence to give himself a cerebral advantage and to always be one step ahead of his opponent - much like we saw happen with Sully and Olynyk in their rookie years.
At the start of the season I think he'll struggle to get any minutes (over Turner, Jerebko and Crowder) but as he starts to pick up the game on a cerebral level and adds some bulk to his frame I think you'll start to find him earning some spot minutes from time to time. I can see him basically replacing Gigi in his role as the 3rd tier shooter / energy guy off the bench.
I feel like the second year is when he'll be more likely to make a significant impact, but if the right situation presents itself (a trade, an injury, etc) and he has an opportunity to get some playing time, I think he'll impress the coach and make an impact in a similar way to how Jerebko and Gigi did last season.
Jordan Mickey
Between Lee, Johnson, Sully, Olynyk and Jerebko I don't think there are a lot of situations we aren't covered for up front, so it's going to make it hard for Mickey to earn much playing time.
Early on, I think he might get the odd spot minutes in situations where we need a more athletic/mobile front line (or maximum rim protection) in which BS might consider pairing Mickey with Amir Johnson in the front court.
As the season goes on I do think he'll get opportunities because:
* Sully and Olynyk are both foul prone
* Sully, Olynyk, Lee and Johnson have all missed games recently due to injury
So at some point or other I feel he's probably going to need to step in and play some decent minutes out of necessity. When that happens I think he might raise some eyebrows with his athleticism, rebounding and shot-blocking - but I also think his ability to earn extended minutes is going to depend heavily on his ability to hit that midrange jumper with consistency.
Overall thought I don't expect he'll get more than around 4-7 MPG for the season, unless there are multiple injuries and/or there's a trade that reduces front court depth.