One thing that Arkansas fans have been able to count on in the three years of the Bret Bielema era is an ability to run the football. That’s no surprise, considering Bielema is a former offensive lineman who has always stayed true to his ground-and-pound philosophy.

The Hogs were ranked just behind LSU, Alabama and Tennessee in rushing last year in just about every category, and fans have been spoiled by the consistency of Alex Collins, who rushed for more than 1,000 yards three seasons in a row. Collins and Jonathan Williams were both drafted in April, and the Razorbacks enter 2016 with a boatload of question marks in the backfield.

There is potential, but there are also plenty of concerns. Up and down the depth chart, there isn’t a single back who’s proven they can be productive on the college level, either because of inexperience or a propensity for injury. When the Razorbacks get together in the fall, the race for the starting spot in the backfield will be wide open and competitive.

Rotation

Collins was a workhorse in 2015, carrying the ball 271 times for 1,577 yards, good for 5.8 yards per carry and 20 rushing touchdowns. He was the go-to guy because Williams – who had rushed for 900 and 1,190 yards the previous two seasons – missed all of 2015 with a foot injury.

There are no obvious choices this year. Kody Walker was granted a sixth year of eligibility and likely will get the first shot, but his career has been riddled by injuries and he even wound up missing the last half of spring practice after requiring foot surgery. He’s supposed to be 100 percent by the fall, but we’ll have to see if he can stay healthy.

Same goes for Rawleigh Williams III, who was carted off the field last October with a scary neck injury. He’s been cleared to play but practiced without contact all spring. It remains to be seen what happens to him in the fall after he gets hit a few times.

The player who has everyone excited is incoming freshman Devwah Whaley. He hits campus as the nation’s No. 3 running back out of high school. He’s going to compete for playing time immediately and could be the main man if Walker and Williams can’t stay healthy. He’s the player to watch in this group.

Chasing 1,000

It’s highly unlikely that Arkansas has a 1,000-yard back this year, because it doesn’t look like anyone will be a featured back through a full 12-game season this year. It’s likely that Walker and/or Williams will get a shot early, but Whaley might become that star later in the season.

What changes the thinking here? If Whaley becomes the go-to guy early, he might get enough carries to make 1,000 happen for UA for the fifth time in four years. Fans and coaches would love to see Walker stay healthy all year because the talent is certainly there to be the workhorse, but his track record with injuries seems to make that improbable.

Play-calling

Arkansas’ offense ranked No. 2 in the league last year behind Ole Miss, and new offensive coordinator Dan Enos was a big reason why. He found a nice comfort level in play-calling and hit all the right buttons in moving this offense down the field. Because he has to replace veterans in key spots – quarterback Brandon Allen, tight end Hunter Henry and backs Collins and Williams are all off to the NFL – it’s going to be interesting to see how the game plans will change.

Word out of Fayetteville in the spring was that Enos was very happy with the play of new quarterback Austin Allen, who’s been waiting for three years for his shot. Allen knows the playbook well, and Enos will have everything in it at his disposal. Enos is the least of the concerns right now.

Greatest concern

Uncertainty is a terrible thing, even in the summer. So the biggest concern is that no one steps up to be a star. With an inexperienced QB in Allen, Enos would love to be able to run the ball well and keep the pressure off Allen. The concern is, what happens if the running game struggles early and Allen is forced to throw too much, especially in bad down-and-distance situations?

One stat that must improve

Improve, or at least stay comparable. That’s the deal with rushing average on first down, especially while trying to protect a first-year quarterback. Last year, Arkansas averaged 5.53 yards per carry on first down, good for third in the league (behind Georgia and LSU) and 24th in the country, according to cfbstats.com.

That kind of consistency would be a huge help to an offense that will fire away with a first-year starter at quarterback in Allen. To keep the chains moving and stay in short-yardage situations would be a huge plus.

Better or worse in 2016

The Razorbacks were fourth in the league – and top 35 or better nationally – in just about every major rushing category a year ago, but they will be hard pressed to even come close to that this year.

Collins and his three-straight 1,000-yard seasons could be counted on for years, and now he’s gone, as is Jonathan Williams. There is talent returning, but every bit of it is unproven, either because of inexperience or a lengthy history of injuries. This one goes to 2015 for sure.