More than 300 of the top players in college football in 2014 received invites to this month’s NFL Scouting Combine, regarded as one of the most pivotal showcases of talent on the path to the NFL Draft.

The combine will span from Feb. 17-23 in Indianapolis, and will feature on-field workouts and off-field interviews and examinations to determine the draft stock of each and every invitee.

Among the hundreds of players who will flood Indianapolis with hopes of standing out in front of NFL scouts, 69 hail from SEC schools. But these five SEC stars have more to prove at this month’s combine than any others as they aim to make a successful leap from college football to the NFL this offseason.

1. Nick Marshall, CB, Auburn: There isn’t a player from the SEC with more to prove at this year’s scouting combine than Marshall, who just two years ago quarterbacked a team to an SEC title and to within 13 seconds of a national championship. Marshall has since changed positions to cornerback, and aside from a week of practices at the Senior Bowl last month there isn’t much evidence to determine whether or not he can handle the position change at football’s highest level. One thing scouts do know is that Marshall is a phenomenal athlete with speed and agility that cannot be taught, and the combine will be his chance to show he’s at least begun to acquire the traits of an NFL defensive back, or at least of an NFL kick returner.

2. Blake Sims, QB, Alabama: Sims is the only SEC quarterback with a chance to be selected before the seventh and final round of this year’s draft, and a strong showing at the combine could draw the attention of teams looking for a quarterback who are likely to miss on Marcus Mariota and Jameis Winston in the first round. Sims showed great athleticism and a great pocket presence in leading Alabama to an SEC title in 2014, and he was above-average in his limited chances to run the two-minute offense, but he was also limited to just one year as a starter and played in one of the most talent-rich offenses in the nation under offensive coordinator Lane Kiffin. Sims must prove his skills can translate to the next level where the game moves faster and his unit lacks a substantial talent advantage over its opponent, and the combine is the first step toward proving he can do it.

3. Sammie Coates, WR, Auburn: Coates may be among the most explosive athletes in this year’s draft class regardless of position, and he may be the single most dangerous deep threat on the outside in the class. However, Coates lacks the consistency many NFL organizations desire, and he is still rounding into form as a wideout capable of more than a vertical route. The combine will be an excellent opportunity for Coates to remind scouts of his athletic excellence while proving he’s more than capable of catching balls across the middle or in traffic along the sidelines.

4. Dorial Green-Beckham, WR, Missouri: Two years ago there wasn’t a receiver in the nation more talented and physically gifted than Green-Beckham, whose incredible length, long strides, fantastic leaping ability and soft hands made him nearly impossible to defend. Seriously, by the end of the year the back-corner fade to DGB was as automatic as an extra point. However, off-field troubles earned him an exit from the Missouri program, and after sitting out last season as a transfer at Oklahoma he’s entering the draft without ever playing a down for the Sooners. Green-Beckham ultimately only has to prove he hasn’t lost his magic touch on the outside, and if he shows flashes of the player we saw at Mizzou two years ago he’ll remain established as a lock to be taken in the first round.

5. Markus Golden, DE/OLB, Missouri: Golden, who played outside linebacker in junior college before transferring to Missouri, may have to adjust back to that position again as he prepares to enter a league growing more fond of the 3-4 defense and placing pass rushers on the outside as standing linebackers. Proving he can make that adjustment will be vital for Golden’s draft stock, as like it or not he was perceived as the Tigers secondary pass rusher to likely top 10 pick Shane Ray in 2014. Golden will have to overcome a number of those kinds perceptions at this combine, proving not only that he can make plays without Ray occupying the attention of opposing defenses, but that he’s capable of outdoing the numbers posted by former Mizzou defensive end Michael Sam at last year’s combine.