It's not a form thing with Rooney, he's on the slide and will be past it soon, he's done physically. Teams always keep their biggest name players around long past their sell by date and then look back at it as a mistake, I'm sure that will be the case here. Kane on the other hand looks like he could be a good player for the next 10 years.
Anyway it doesn't matter, Rooney will start if he is half fit, and it should really be his last chance as a starter in a tournament.