I put my treinee as starter, backup and reserve. I am doing this for every trening and I didn't see anything like that. And my instuctions are always stick to the plan with substitutins.
I can imagine that first game in this week was random and this things just happens, but when happens two time in the row, there is probably somthing wrong. I am assuming that new coach is the reason. Is this possibility?
And I can't agree, that this happens when I already secure victory, because my treinee was replaced by starter in another position.