Its a long shot, but I've seen lots of comparisons to Purdy and Russell Wilson. Very similar to both in college, although not quite as accurate (although still very good). He also improved a ton between his junior and senior season, so he probably has room to improve. Seems like he's highly intelligent, processes data well, anticipates throws and throws a great deep ball (like Wilson, not Purdy).
I have a feeling that the coaches will figure out if he's a future starter this year, even if he doesn't play much. I don't think the 49ers coaching staff were stunned by Purdy's success. They knew early that he was special and didn't flip out when the injuries began. I think the Vikings will know early too. If he's a stud, they won't worry about an early QB next year. If he's not, then they might use an early draft pick next year (if they decide not to extend Cousins, which is still possible).