Rooney has underachieved at international level (and club level in recent times too), but he has still been an important player for England - not least in qualifying when he was top scorer.
He can still play a key role. He is best in the #10 role behind a centre forward (Kane) and with two quick wider players (Vardy, Welbeck, Sterling - and others can fill those roles). He is still one of only a few English players who is comfortable on the ball, can link up play and on his day, can produce genuine quality. It means playing him instead of Alli, but that isn't necessarily a problem. Alli is 19 and inexperienced. He can't be expected to play every minute of every game against opponents who will make life difficult for him by closing down space. All the teams at the Euros are well organised and can defend. He might be best as an impact sub where his energy and running later in the game will have greater effect.
Rooney is also versatile - he can play any position in a front three or deeper and even when he's not at his best, his workrate is second to none. How many other forwards track back and cover like he does? He still has a lot to offer and you know he will be selected for the squad. There is, however, no reason to think Woy will be dogmatic about playing him. Or subbing him if he does play. If he doesn't merit selection for a particular game, he shouldn't play. But it strengthens England to have him in the squad. And experience in a young squad is valuable. Like all level top level sport, teams rarely blow opponents away. There are key moments in games which swing the balance. Experience at those times is often crucial.
