I've made this point several times about their team, maybe it is wishful thinking on my part but I do think that it will affect them. Mason seemed to never tire no matter the pace they played at and always fell forward, Robinson is obviously a top flight player, and you can tell from the coaches comments what they thought of Prosch.Selma, they may return 8 starters on offense, but they lost 3 important starters that made that offense go ( Robinson, Mason, Prosch). Gus might be able to find adequate replacements for them, but IMO it won't be easy.
When you get down to it their ground game was the absolute key to their success last year including most of the passing that Marshall got done. These three guys accounted for a gigantic part of the reason that their run game was so effective.