The teammate who gets fewer minutes still deserves a clear account of their role.

Silence is the usual way of handling the people at the edge of a team, and silence gets filled with the worst available explanation. Someone left out without a word will decide they are disliked or being managed out, and either is more corrosive than an honest account of where they stand. Clarity is not the same as promotion.

If you lead anything, tell the least-used person what you are looking for and what would change your mind. Say it directly and without inflating it. Then check that you gave them a real chance to show it.