Keep in mind two things, though, when you consider whether Carnes can challenge this fall:
1) We scrapped the old offense, and though the new one is very similar, all 3 guys are learning a new system. So, Carnes theoretically could pick it up faster than the other two, even though they've been here longer.
2) Taylor was not 100% today, and it could be quite a while until he actually is. What if this turns into one of those nagging injuries that follows a guy around his entire career? God forbid, but it could happen. Is a gimpy Martinez really the best choice to run our offense? We saw what it looked like at the tail end of the year, and it was not pretty for our offense.
Regarding #1 -
this offense is basically being tailor-made for Taylor. If he doesn't have the best grasp of this offense of all our QBs, he'll never start another game.
#2 - This is a good point. I would hope that Carnes progresses well enough to be able to functionally lead this team if Martinez goes through another injury spell. If not... I'm not sure we can succeed with Cody.
Last year's offense was just for Taylor as well.
When we ran into a team with an athletic defense and a few game films, it was pretty ugly (Texas).
There's a reason nobody else recruited him at QB, and it isn't because we found a hidden gem nobody else knew about. I don't really envision him improving much in the most important areas (mechanics, pocket poise, making reads, etc.). I could be wrong. But winning the Big 10 without a passing game will be really tough.
I know he hasn't played a snap of college football, but Carnes sure looks like a solid passer. Not sure how he'd perform overall against the likes of OSU and Wisconsin, but I don't think we should rule out using him this season.