The Tampa Bay Buccaneers need to make some additions at running back, even though they are bringing back their starter from the end of the 2017 season. There are a number of ways the team could approach that task, and one of them was in motion – at least from an evaluation standpoint – on Friday.

After several days of medical testing, interviews and weightlifting at the 2018 NFL Scouting Combine in Indianapolis, the on-field workouts finally began at Lucas Oil Stadium. The first position groups to run though their drills were the offensive linemen, special-teamers and running backs. That latter group is considered particularly deep – if not necessarily loaded with certain first-round picks – and its collective work in the 40-yard dash was of great interest.

The Buccaneers have three tailbacks under contract for 2018 after releasing Doug Martin in February. Third-year man Peyton Barber is that aforementioned returning starter, and veteran Jacquizz Rodgers has handled lead-back duties for the Bucs at times over the past two seasons. First-year player Dalton Crossan, just signed last week, is an undrafted and unproven commodity yet to take a regular-season snap in the NFL. Head Coach Dirk Koetter said the Buccaneers are likely to carry four tailbacks in 2018, so there is work to be done.

Buccaneer decision-makers like Koetter and General Manager Jason Licht are not going to share their draft plans, for obvious reasons, so it remains to be seen if the team's backfield additions will come from the draft. Still, Licht and his entire crew of personnel evaluators was on hand Friday, of course, and they got to see a group of talented backs, each one trying to separate himself from the crowd by some measure.

Penn State's Saquon Barkley has probably already done so, as he's considered a potential top-five pick and the one back most likely to instantly transform his new team's offense in the manner of recent high picks Ezekiel Elliott and Leonard Fournette. Barkley is the complete package as a runner – power, speed, elusiveness, vision – and scouts also rave about his work ethic and character. Still, he came to the Combine feeling like he had something to prove; specifically, he wants to be seen as an all-around threat who can make a big impact in the passing game, too.

Barkley said the Penn State coaches challenged him to improve that aspect of his game throughout his tenure with the Nittany Lions, and indeed he improved his receiving numbers every year, peaking with 54 catches last season as a junior.

"If you want to be elite – if you break down the running backs, if you break down the top five backs [in the NFL], all those backs can catch the ball out of the backfield," said Barkley. "All those guys are special with the ball in their hands, and that's something I strive to be. I want to be one of the best. Obviously you've got to respect the people that did it before and the people that are doing it now and learn from them. You see those guys and how they're dominating games not only running the ball but catching the ball out of the backfield."

If Barkley is drafted as quickly as many expect, he won't be in play for the Buccaneers, who pick at #7 in the first round barring a trade. In the collection of seven experts' mock drafts on NFL.com, all seven had Barkley off the board by the fourth pick, and four of them slotted him at #2 overall. As we noted several weeks ago, however, the running back class as a whole doesn't have a lot of representation in the various first-round mocks; rather, there may be a run on the next tier of prospects early in the second round. That's a strategy the Buccaneers have used to pretty good effect in the past.

That next tier includes the likes of LSU's Derrius Guice, USC's Ronald Jones, Auburn's Kerryon Johnson and the Georgia duo of Nick Chubb and Sony Michel. All could come off the board somewhere late in the first round or early in the second, around where the Buccaneers pick 38th overall in the second frame. They were jockeying for position in that potential run on backs at the Combine, and one of the most common refrains was proving that they were complete backs. As such, names like Le'Veon Bell and Alvin Kamara were repeated frequently during the running backs' Combine media session.

Johnson, in fact, has heard that direct comparison to Bell when it comes to his running style, which he obviously takes as a compliment while emphasizing that no two backs are the same.

"We both have a habit of stopping in the backfield at times," said Johnson. "I think that's the main thing that people see. We're different, but the comparisons are nice. It's cool. You could be compared to a lot of people, but one of the best in the league – in my opinion the best running back in the league – that's high praise."

Johnson credited players like Bell and Kamara for transforming the way backs are used in the NFL, and every prospect at the Combine would like to convince teams they can be used in the same way.

"What do I want to prove most? Probably my speed and quickness…and catching the ball," said Chubb. "I think over the past few years the running backs have done a great job of coming in on the NFL level and putting their position in a better situation. Teams are using their running backs a lot more in passing situations."

Unlike Barkley at Penn State, Chubb wasn't much involved in the passing attack for the Bulldogs, so it's obvious why he would want to convince teams that was a factor of his team's offense and not a deficiency on his part. Similarly, Jones is a little smaller than some of the other backs and seeks to show that he can handle the very important job of pass protection, nearly a prerequisite for seeing extensive playing time in the NFL.

"I didn't do too much of it but I'm very comfortable doing it," said Jones, who intends to increase his weight to 210 pounds by USC's Pro Day. "I know how important it is at the next level to protect the money man, the quarterback next to us. I look forward to getting better at that ability."

On the other hand, Guice chose to emphasize his strength and show that he could do one important thing better than anybody else in the field. As such, while his fellow backs were name-dropping Bell and Todd Gurley, Guice compared his own style to that of Marshawn "Beast Mode" Lynch. He said he frequently watches film of Lynch and thinks about his approach when he's about to take a handoff.

"We didn't really pass as much in college like other running backs do, but as a runner in between the tackles, in my opinion there's no one better than me in that area, point blank," said Guice. "I run hard, I hardly ever get tackled by one person and I'm very powerful. I get a lot of hidden yardage."

That could be enough to make Guice the second back off the board after Barkley. Or maybe teams will appreciate Jones's explosiveness or Johnson's patient style. What's clear is there is a of talent at the position at this year's Combine, and a lot of young players trying to prove they can do it all on the next level.