He is just fine. You just need to understand as well as the coaches that he is a 3rd line center. He isn't a top 6 player which is fine.
He looked a million times better in a more defensive role on the 3rd line with Abdelkader flanking him. Hopefully that's a position he settles into and can thrive at. Having a 3rd line that can be used in a shutdown scenario while also chipping in some offense is really valuable.
I know the Wings have traditionally aimed for 3 scoring lines, but lately that's really diluted the scoring talent across the top lines. Overflow the top 2 lines with scorers then rely on your bottom 6 to grind out dirty goals and take defensive draws. Get size and speed in that bottom 6 and make them a real pain to play against. Sounds like that's part of the plan, following both Holland's and Blashill's quotes. More defined roles and such.