Top 2015 prospects with most to prove

Both Marcus Mariota and Jameis Winston have significant progress to make prior to the 2015 draft. USA TODAY Sports, Getty Images

On Wednesday, Todd McShay released his Way-Too-Early 2015 Mock Draft. Yes, on Wednesday.

While the 2015 NFL draft is still more than 11 months away, it got me thinking: Who among this year's class of top-shelf college players will have the most to prove when the first whistles of the season start blowing Aug. 28?

Here are five projected first-round picks you should be keeping an eye on, because NFL front offices sure are.

Jameis Winston, QB, Florida State Seminoles

Wait, a Heisman winner has something to prove? Heck yeah he does, and while it does have something to do with football skills, it's really about what multiple NFL scouts have described to me over the years as the "knucklehead factor." From broken windows to sipping free sodas to “CrabGate” to the much more serious accusations of sexual assault, he hasn't been able to sidestep tales of questionable decisions.

The bad news for Winston is that there are already whispers among NFL folks that his immaturity is getting worse instead of better. The good news for him is that there already has been a precedent set that shows he can erase those questions as soon as the games finally begin.

"Last summer we were saying all this same stuff about another defending Heisman winner," one scout said, referring to the media madness that was preseason Johnny Manziel. "But once the games started and he stepped right back into being his old self on the football field, all that mess went away pretty quick. Yeah, he dropped through the first round some, but he was still a first-rounder."

On the field, it was widely reported throughout last fall that many NFL personnel evaluators would've rated Winston as the No. 1 pick had he been eligible for this year's draft. He can go downfield when he wants and has a built-in field vision that guides him through smart short-passing windows as well. But nearly all of those evaluators were still quick to point out the benefits of staying in school at least three years. When it comes to quarterbacks, pro front offices prefer four years on campus.