We're taking a look at each position group as Alabama prepares to open spring practice in March. The fourth of a 10-part series looks at the running backs.

Departed:

Derrick Henry who won the Heisman Trophy and set numerous school and SEC single-season records last season.

Kenyan Drake

Projected depth chart:

RB 1: Bo Scarbrough: Former 5-star recruit who scored 1 TD last season OR Damien Harris: The No. 3 running back for most of last season who had 46 carries for 178 yards and a TD.

RB3: Ronnie Clark: Rushed for 20 yards on 5 carries OR Xavian Marks: Former track star who only received one carry in 2015.

New in spring: No one.

Arriving in the fall: B.J. Emmons and Joshua Jacobs

Outlook: Bo Scarbrough is already hailed as the next heir to the running back throne, but Nick Saban will have as little experience at the running back position this spring as he's dealt at Alabama. Alabama loses its top two running backs from last year's national championship team, one of which happened to win the Heisman Trophy and dominated opponents on the Tide's title path.

Henry can't simply be replaced. At 6-foot-3, 242-pound he's too big, too unique to simply plug someone in and expect him to replicate the production. Kenyan Drake didn't have the senior season he was hoping for - injuries again limited him - but he was a necessary change-of-pace back that opened up inside running lanes for Henry.

The top two candidates to replace both are Scarbrough and Damien Harris. The sophomore running backs combined for 64 carries for 283 yards and two touchdowns. Harris had the edge early in the season with Scarbrough serving a four-game suspension, though by the end of the season it seemed like the Tuscaloosa native had supplanted Harris at the No. 3 spot.

Scarbrough is the most physically reminiscent of Henry - he stands at 6-foot-2, 240-pounds - but has had trouble staying healthy in the past. He has as good a shot of anyone as emerging as the top running back if he can stay healthy and adequately pass protect. Harris, a former five-star recruit out of Kentucky, will have a similar opportunity.

The other running backs to watch this spring are Ronnie Clark and Xavian Marks. Neither made a significant impact last season, but one will receive a good chunk of reps during practice as the No. 3 running back.

One other thing to watch: Saban left the door open to add a graduate transfer running back the way Alabama recently did at receiver with Gehrig Dieter. The perceived top option Barry Sanders Jr. recently transferred to Oklahoma State, but it's something worth watching especially if the Alabama head coach doesn't like what he sees at running back this spring.