PHNX Cardinals Podcast had Mina Kimes on, they were talking about Marv.
She thinks Petzing needs to feature him more, that it feels like we're just running the same offense we ran last year and oh btw every now and then here's a play for Marv. Said we're running too many low % plays for him. She took for granted he'd be NFL ready and polished so she's a bit surprised he's not looking that way.
FWIW the announcers said the coaches confirmed on the play where Kyler had to call timeout because guys weren't lined up, Marv was the guy who was NOT lined up right.
Kimes loves him, said he can run the whole route tree and she thinks we should take more advantage of that in the offense. But she did agree with the podcasters, it looks at times like he's not comfortable, he's not sure what he's doing and it shows in his routes sometimes, which was his strength in college.
Also on Kyler said he's definitely not been perfect but she says he's playing well but can play better.