By any means possible – and the draft is one option – the Detroit Lions have to improve their running game.

This year's class of running backs is deeper than usual, with Leonard Fournette, Dalvin Cook and Christian McCaffrey at the top and solid prospects through the middle rounds.

The run game has been a problem in recent seasons, and last year was more of the same. The Lions ranked 30th.

"We didn't run the ball well," head coach Jim Caldwell said at the recent NFL Annual Meeting. "That's on us (the coaching staff). I've got to do a better job at that."

Which way to go for help? Big back, or speedster?

"You can argue both points," Caldwell said.

Injuries hurt last year. Ameer Abdullah went out for the season in the second game with a foot injury, and Theo Riddick missed six games. Having those two back will help – and so would adding a back in the draft.

Draft priority: High. Stats don't lie.

Free agent RB impact: None. The draft awaits.

Detroit Lions RB Draft Breakdown: Depth chart, stats, Caldwell's comment, capsule highlights of the top 5 running back prospects, other notable potential draft candidates and the spotlight player:

Depth chart: Ameer Abdullah, Theo Riddick, Zach Zenner, Dwayne Washington, Mike James, Michael Burton (fullback).

Caldwell's comment: On 2016 rookie Dwayne Washington: "Don't forget Dwayne Washington, who's a big back, who's strong, who's developing."

2016 team rushing ranks: 30th in yards per game (81.9); 27th in yards per attempt (3.7); tied for 26th in TDs (9); tied for 25th in gains of 20 yards or more (6).

100-yard drought: The Lions have gone 52 regular-season games and two in the playoffs without an individual 100-yard rushing game. Last to do it was Reggie Bush, with 117 yards against Green Bay on Thanksgiving Day of 2013.

Top five running backs:

1. Leonard Fournette, LSU: Speed (4.51 Combine 40) to go with size and power (6-0, 240) make him the top RB prospect in a deep group.

Stats line: 300 carries for 1,953 yards, 6.4 average and 2 TDs in 2015; coasted through 2016. Limited experience as a receiver.

2. Dalvin Cook, Florida State: 22 reps in the bench press eased concerns about shoulder injuries, and he runs with more power than his 5-10, 210-pound frame might indicate.

Stats line: Three seasons of 1,000-plus yards, with a career total of 4,464, 46 TDs and a 6.4-yard average.

3. Christian McCaffrey, Stanford: Showed his athleticism in his Combine workouts – 4.49 40, 37-5 vertical jump, 10-1 broad jump.

Stats line: 6,987 all-purpose yards in three seasons: 3,922 rushing, 1,206 receiving on 99 catches, 380 on punt returns, 1,479 on kickoff returns.

Versatile, but is he a lead back or vice-chairman of the committee?

4. Alvin Kamara, Tennessee: He was at three schools in three years out of high school – redshirt freshman at Alabama in 2013, a transfer to Hutchinson Community college in 2014 and a transfer to Tennessee.

Stats line: For the Vols he rushed for 1,294 yards and 16 TDs and caught 74 passes and seven TDs.

Combine performance could push him up the board, but he looks like a Friday pick (second round, or third).

5. Joe Mixon, Oklahoma: Minus the obvious baggage and controversy, Mixon is a legit top 10 prospect who'll be drafted lower. He had a spectacular Pro Day: 4.43 40, 21 reps in the bench press, 35-inch vertical jump.

Stats line: Sharing time in 2016 with Samaje Perine (who rushed for 1,060 yards), Mixon had 1,274 yards rushing, 10 TDs and a 6.8-yard average. He's also an accomplished receiver, with 37 catches, 14.5 yards per catch and five TDs.

If you draft him, be prepared to hear the uproar. If you don't, you might hear it the first time you play against him.

Others: Marlon Mack, South Florida; Samaje Perine, Oklahoma; Wayne Gallman, Clemson; Kareem Hunt, Toledo; D'Onta Foreman, Texas; Jamaal Williams, Brigham Young; Jeremy McNichols, Boise State; Corey Clement, Wisconsin; James Conner, Pittsburgh.

RB Spotlight – power train: At 6 feet and 233 pounds, D'Onta Foreman of Texas is built to be a power back. And he was just that at Texas.

As a one-year starter, he carried 323 times for 2,028 yards and 15 TDs. He had a one-game high of 341 yards on 33 carries against Texas Tech, and an even 250 yards against Baylor and Kansas. That adds up to 823 yards in three games – a season's worth of yards for most backs. Ball security has been an issue for Foreman, and he has to prove he can catch the ball and block.

Foreman helped his stock at his Pro Day. He ran the 40 twice and was timed in 4.45 and 4.46 seconds.