We don't need Suns fans to tell us this inevitable fact because whether injured or not it happens as players age. Hence the reason to incorporate some style and grace as players age and realize athleticism soon fades.
But to defend Amare, he isn't in mid-season form because... well because this is the pre-season for him, not mid-season. Let's wait until his mid-season and for him to gel with the unit he will be with (probably starters) until we evaluate him.
Have you ever lost explosiveness or quickness returning from injury only to recover it over time my athletic freak fellow poster? I have and it takes time to return.
That to me is different from cartilage erosion.