There is no evidence that Rosenior is planning to use him in the first team. You're excited about the idea of a young player breaking through which is understandable but it's based on very little. Listen to Rosenior's comments about him the other night, he made it pretty clear he has a lot to improve on before he's in the first team equation. Allahyar and Longman as our best options leaves us weak on the wings, yes, but that's why we're signing two more wingers and also playing Vaughan there. Jarvis is not overtaking all of these players because he scored two goals in pre-season. In fact he'll probably be the one to get less pre-season minutes when Traore and Lokilo are ready to play.
None of that is a criticism of him, it's just the reality of his status in the squad and how many senior players we have and are signing in his position.