Wiseman is being prioritized over him.I don't understand the lack of Kuminga minutes.
They see Kuminga as a wing-big hybrid, and they're not willing to continue with the experiment of having both of them out on the floor together, largely because Wiseman typically kills any lineup he's in, which is even worse if you have him out there with a bunch of young guys, especially if he and Kuminga are the frontcourt duo. It's why Wiseman's minutes have been alongside a more experienced player (Dray or JaMychal) in the more recent games.
They're basically treating the regular season as an experiment, which they did last season, until they find the right formula for the playoffs.