Posted by ESPN.com's Adam Rittenberg
Tuesday's blog identified several potential Big Ten stars whose names you might have known before their productive springs. Now it's time to look at five players who truly came out of nowhere to become factors heading into the fall.
1. Ralph Bolden, RB, Purdue -- When it comes to this category, no one in the Big Ten came close to Bolden this spring. After recording just 16 carries for 28 rush yards last season, Bolden exploded for 420 yards on 66 carries (6.4 ypg) with four touchdowns in four scrimmages this spring. He entered practice well down the depth chart but exits it as a strong candidate to win the starting running back spot.
2. Trenton Robinson, S, Michigan State -- Head coach Mark Dantonio couldn't stop gushing about Robinson, who stood out this spring as injuries created opportunities in what will be a very deep Spartans secondary. Robinson, a sophomore, entered the spring listed as the third-string free safety but should see a lot of time on the field this fall.
3. Devin Smith, CB, Wisconsin -- The Badgers' secondary figured to feature plenty of competition this spring, but few envisioned Smith, primarily a special-teams player last season, to make a push for a starting job. The sophomore impressed the coaches with his coverage skills and ended up as a co-starter with Niles Brinkley on the post-spring depth chart.
4. Dace Richardson, G, Iowa -- Richardson isn't so much an unknown name as he is a name most forgot after numerous injury problems. But after his career was essentially declared over last summer, Richardson fought back to the field and put himself in position to compete for a starting guard spot (he played tackle earlier in his career).
5. Jeravin Matthews, RB, Northwestern -- Matthews got on the field as a true freshman last fall, which is saying something at Northwestern. But few expected him to compete for the starting running back spot after moving over from wide receiver. His speed stood out to the coaches, and his running style and versatility fits the mold of what Northwestern wants from its backs.