It hasn't occurred to anyone that maybe we'll be running a lot of spread offense formations. I mean it's known that Shanahan spent time attending Patriots' practices studying what they do. And the Pats run a lot of the spread offense with Brady in the shotgun. Or that he spent time with Urban Meyer learning about his spread offense. And not to mention the Texans (where Kyle Shanahan just was) ran a lot of spread offense formations.
And then on top of all that is the fact that Bradford has shown (his freshman year) that he can also be successful behind center.
In conclusion, Bradford will do just fine...and if you're concerned about him just draft Jevan Snead!