My early thoughts on Mathis.
1) Looks very raw in his video.
2) He was the #261 ranked player and Plumlee #267 or whatever.
3) My preference is let Mathis redshirt because he is going to be raw. Just let him play the four games to get a taste and redshirt.
However, my feelings are that he will not be the starter when Fromm leaves. The way Kirby is recruiting, in 2020 or 2021 we will sign a 5 star "top 3" type QB who will take over. So, after thinking, I say LET THE KID PLAY this year. All mop up duty. Let him sling it around the field. You may have a diamond in the rough and it would be nice to know. If he isn't, then you see it, and can sign the next 5 star in 2020.
My point being: Jim Chaney, use this kid unlike the way you used Fields----let him use his instincts.