A record 135 underclassmen declared for the 2019 NFL Draft, and over 20 of them were running backs, helping to fill a group that will look to prove itself at the NFL Scouting Combine in a couple of weeks. Here's who you need to keep a close eye on at the running back position in Indianapolis.

Top Pick

This is the player who I feel is at the top of the class coming into the event.

Josh Jacobs, Alabama

I could have gone another way here, but his upside is very high. It could be argued that Jacobs isn't even the best back on his own team as we stand here today – I believe that honor goes to Damien Harris, who started ahead of Jacobs for the Tide. Jacobs can impact the game as a runner, as a receiver, and as a special teams maven. He displays natural power and short-area burst with the ball in his hands. The one concern I do have about him is that he can be a bit indecisive at times approaching the line of scrimmage, but with his ceiling, it's hard not to have him as the top dog at running back in this class. I expect him to go off the board anywhere in the first two rounds.

Workout Warrior

This is the player who I expect to see perform best in the athletic testing portion of the workout.

Devin Singletary, Florida Atlantic

The junior, who has scored more touchdowns than anyone in college football over the last two years, has been a dynamic player for Lane Kiffin. A large reason for that is his athleticism. Singletary has LeSean McCoy-esque lateral agility, speed to burn in the open field, and the ability to make defenders look silly one-on-one in space. His physical tools should put him in position to test extremely well on the turf in Lucas Oil Stadium, and he should be a Day 2 selection in April.

Trust The Tape

This is the player who I don't expect to test off the charts and is a better football player than he is an athlete. With that in mind, don't drop him down the board with a subpar workout!

David Montgomery, Iowa State

My guess is that Montgomery won't burn up the track at the Combine, but that's OK. I'm not expecting him to thrive in Indy. The junior runner's strength isn't his straight-line burst, but rather his contact balance and lateral agility. Montgomery excelled at making the first man miss at the college level and, in ways similar to Kareem Hunt coming out of Toledo (who also did not work out well), I think he'll be able to do that well entering the league. Montgomery is one of my favorite backs in this draft. I'd throw Mike Weber from Ohio State into this category as well as a player who may not light up the stopwatch but is just a good, solid football player.

Stopwatch Shocker

This is the player who I expect to see test better than most in the media believe they will perform based off of current projections.

Miles Sanders, Penn State

It's not easy stepping in for one of the best to ever do it, but Sanders had to do that this year for the Nittany Lions as he tried to replace Saquon Barkley.

The junior held his own in that regard, rushing for over 1,000 yards on his way to being named second-team All-Big Ten. No one will mistake Sanders for Saquon from an athletic standpoint. In fact, that's one area where I have a bit of a question for Sanders transitioning to the NFL – is he athletic enough to set himself apart and consistently make that first man miss? If you've been following the Combine in recent years, however, one thing has consistently been true – Penn State players always test like freak shows. Whether it's been Barkley, Mike Gesicki, or Troy Apke last year, or Chris Godwin the year before that, PSU has shown out in this event. This is a stab in the dark, but I bet Sanders, who ran relays at Woodland Hills high school in Pittsburgh (another omen for success), tests better than most expect.

Will Kill The Drills

This is the player who may or may not be a great athlete, but he will look the best in the position-specific drills after the athletic portion of the workout.

Damien Harris, Alabama

Harris grades out as the best player in this class at the running back position in my eyes, but he doesn't have true explosive speed in the open field and isn't the kind of dynamic athlete in space like Jacobs or Singletary. My guess is that he'll have a solid athletic workout, with nothing eye-opening, but that won't change my mind about him. One area where he does stand out, however, is with his feet. He's got outstanding feet to navigate through traffic, and that will show up in the bag drills. Harris also boasts great vision, is a strong pass protector, has very few negative runs on film, and has plenty of tread on the tires despite starting 40 games for the Crimson Tide over his career. I'll take this kid on my team any day, and I think he'll end up being a second-round choice in a couple of months.

Most To Prove

This is the player who has the most to prove away from the field, whether it's during the interview process, medical examinations, or even the weigh-ins.

Dexter Williams, Notre Dame