I think Rooney has a lot to offer, but the sooner he is stripped of his guaranteed starter basis, the better. He's not the player he was, and hardly ever makes something happen out of nothing. Which a no.10 should. He's still a useful player, and he will still score goals in the premier league, which is ultimately the most precious currency in football; but I rankle at the idea that he is undroppable. I am hopeful that Mourinho is going to show little sentimentality on this issue. As Micki finds his feet, and the season progresses, I expect he and Rashford to be taking that starting berth from Rooney.
For the moment, I think Jose is doing the right thing; and integrating his new players into the team, and playing a consistent XI. Rooney is a huge influence in the dressing room, has had a huge career; and I suspect Jose wants to see what he gets out of him. If he doesn't perform, then I believe he will be phased out appropriately. This isn't LVG time anymore. I just think it would've been the wrong thing to come in, and drop Rooney without giving him a chance to claim the spot for himself. His history and previous quality merits that. Especially when his competitors are a new signing from a foreign league, and an 18 year old.
This is a results business, and it was important to get off to a good start. He's focused his changes and energy in the right places so far.