>>31835757I think Rockruff will be similar to Pikachu but closer to Rowlet.
At home and at school it'll walk around with him like it currently does, but on trips into forests, caves or whatever we'll see it in its Pokeball similar to how Rowlet is either in his ball or in the backpack.
The one thing SM has done exceptionally well is making Alola feel "whole". Its an island, and seeing background characters, Pokemon, and the people going about their lives is fresh compared to the unimportant characters we've had filling the streets in past regions.
Litten has a life outside of Ash.
Rowlet, while with Ash, stays true to its character and naps in the bag, his pokeball or wherever it happens to be.
The same with Rockruff, it currently stays at the lab when Ash and Kukui head to the school, it joins them on adventures like at the beach and has its own goals.
It's a part of the cast who has lived on the island longer then Ash has. I can't see it being confined to a Pokeball unless Ash is Island hopping or doing something that doesn't require it to be out.
If he's hanging out in class, at the lab, on the beach, at a store or something I'm fully expecting pupper to be around.