I'm not sure if "gets assigned" is fully accurate given the number of injuries - but I think at the very least, long term, what you see is what you get with Asante - and that's a very good CB...
You get quality play, and a perfect guy for a bend but don't break system - but if you're looking for INT and sack stats he's not your guy.
I think he knows this and wants to have a big season but thus far I think the defensive playcalling with Asante in at starting CB has been somewhat conservative.
Maybe they take some constraints off him this year to see if he can play big? Or maybe they stay conservative with a bend/don't break.
In any event at the very least he'll have another good season and could be signed for reasonable money. If that happens I think he'll eventually become the #1 CB he thinks he is now and it will be a great signing/