ZN is spot on with this perspective. It was unexpected that we kept all 5 lineman (basically) healthy throughout the year last year, which is a rare occurrence. The only backup we have that has starting potential in my mind is Austin Blythe. Cornelius Lucas has size and possible RT starter, but is a UFA. That being said, Whitworth won't be getting better and we can only hope he maintains his level of performance and remains injury free. May go to LG or RT if we have a upgrade at LT in year or two. Saffold, always gets injured, looks serious but you can count on him back in next series. Much different player beside Whitworth than G Williams. John Sullivan won't hurt us and important for line calls, but $7.5 M per year probably exceeds his value on the field. Jamon Brown, who Fishers exclaimed as a long term future pro bowler has not lived up to expectations. I thought by now, Havenstein would have the makings of a NFL body and from my observations, looks like he went the other way. Many Olineman have bellys but they are "solid" if you know what I mean, where Rob is the classic Pillsbury doughboy physique (e.g. Hank Fraley from local RMU).
Summing up, I think we should go BPA at # 23, but will be fine if BPA is a OT like McGlinchey, Brown or Williams. They would be available at # 23 for a reason, so not claiming they are sure fire future starters but would trust Aaron Cromer to make that selection.
