Ezekiel Elliott, Jason Spriggs among biggest winners on first day of NFL Combine workouts

The NFL Combine is finally underway. Players are beginning to stand out, in ways both good and bad. For now, I'm going to take a look at five guys who stood out on Friday, improving their draft stock and, potentially, giving themselves a chance to be selected earlier in the draft and earn a more lucrative rookie contract.

Friday's workouts featured running backs and offensive linemen. Last season, running backs Jeremy Langford, Karlos Williams and David Johnson were three of the top performing running backs at the combine. All three backs were fantastic in their rookie seasons, proving that on occasion, good combine results can be an indicator of a player's true abilities. Offensive linemen Ali Marpet, Jake Fisher, Ereck Flowers all impressed as well, boosting their respective draft stocks.

Most impressively, Virginia Tech tackle Laurence Gibson was one of the combine's top performers despite earning a draft grade giving him less than a 50-50 chance of making an NFL roster. As a result of his impressive combine, Gibson was selected in the seventh round of the 2015 NFL Draft and eventually made his way to the Chiefs' practice squad.

5 players who increased their draft stock during their Friday workouts

Running backs

1. Keith Marshall, Georgia

Keith Marshall ran the best 40-yard dash of any running back, at a jaw-dropping 4.31 seconds. The running back who once shared a locker room with Todd Gurley is a satellite back at best, but his insane 40 time will all but guarantee that Marshall will be selected in this year's draft. Former Steelers running back Dri Archer was selected in the third round of the 2014 NFL Draft after running a 4.26-second 40; it wouldn't be surprising to see Marshall taken in the middle of the draft like Archer. Marshall also displayed incredible strength, with 25 reps on the bench press. Marshall's 25 reps were the most among all true running backs who worked out on Friday.

2. Daniel Lasco, California

Lasco killed the combine, and his name should start popping into many draft conversations very soon. The 23-year-old running back was labeled as a "one-year wonder" in his NFL Draft Profile due to injury concerns and a lack of vision, but his impressive combine will force teams to re-evaluate his value. Lasco was a top performer in the 40-yard dash (4.46 seconds), vertical jump (41.5 inches) and broad jump (135.0 inches). He also managed 23 reps on the bench press and solid times in all other drills. Originally slated to be drafted as a player to fill out teams' rosters, Lasco's stock could help him jump up a round or two in the draft. Lasco looks like a potential superstar special teamer, and he could even become a solid running back if he stays healthy.

3. Ezekiel Elliott, Ohio State

Ezekiel Elliott is widely regarded as the top running back prospect of the draft, so he had much more to lose than gain on Friday. Despite this, Elliot still managed to impress. The running back measured in with massive 10 1/4 inch hands and ran a blazing 4.47 second 40. He only performed in two other drills and wasn't ultra-impressive, but the running back did enough to solidify himself as the top running back in the draft.

Offensive Linemen

4. Jason Spriggs, Indiana (OT)

You can't do much more to boost your draft stock than what Spriggs did on Friday. The offensive tackle was a top performer in four different events, and even his measurements stacked up among the best offensive linemen. Spriggs has massive hands and long arms, and at 6'6", he has the prototypical height of an offensive tackle. One of only two tackles to run the 40 in under five seconds, Spriggs has shown incredible athleticism. Coupled with some impressive tape, it wouldn't be surprising to see the tackle jump into one of the first two rounds of the draft.

5. Christian Westerman, Arizona State (OG)

Westerman has the prototypical size of an interior offensive lineman, with long arms and "bear paws for hands." A 5.18 second 40 time and 34 reps on the bench will both massively boost the guard's draft stock. Originally slated to be taken in the third or fourth round, Westerman could potentially jump as high as the early second round. In my eyes, Westerman had the best combine of any interior offensive lineman. His impressive performance, coupled with some fantastic tape, should catapult the guard's draft stock and could help the lineman make a lot more money than he originally would've made.