Different kind of spring for Mariota

At this time last year, Marcus Mariota was a relative unknown. Now, he's a Heisman contender. Things have certainly changed for the Oregon quarterback in the past 12 months. Ivan Maisel writes about two QBs who burst on the scene in 2012 -- Mariota and Johnny Manziel -- to see how they've changed.

Click here to read Maisel's article.