The Mississippi State offense ranked third in the SEC and 23rd in the nation in rushing last season, amassing an average of more than 233 yards per game on the ground. First-time starting tailback Josh Robinson rushed for 1,200 yards and 11 touchdowns, and has since departed for the NFL in the aftermath of his career year.

Robinson was certainly a superstar for the Bulldogs last season, and he’ll be missed as Dan Mullen and company aim to duplicate last year’s 10-win feat this fall. But as insensitive as it may seem, J-Rob is replaceable. Very replaceable.

In Mullen’s six seasons as head coach at MSU, four different tailbacks have assumed “featured back“ title in his offense. All four ran for 1,000 yards in a season at least once in that six-year span. In fact, the only year Mullen didn’t boast a 1,000-yard back was during the injury-plagued 2013 season, when then-senior Ladarius Perkins returned from a 1,000-yard campaign in 2012 but could never stay healthy enough to repeat the feat.

Mullen’s backfield has always maintained a “next man up” mantra, and it’s served him and the program well since 2009. It appears set to work in the Bulldogs’ favor again in 2015, as the program has two experienced tailbacks it can turn to to carry the run game (no pun intended).

Rising juniors Ashton Shumpert and Brandon Holloway combined to rush for 568 yards last season at an average of more than six yards per carry as co-backups to Robinson. Holloway is the quick slasher who can get the edge and make defenders miss in the open field; Shumpert is the power back of the tandem, outweighing Holloway by more than 50 pounds and using that extra muscle to pick up hard yards between the tackles.

No matter how Mullen plays it — whether he picks a No. 1 to carry the load this fall or allows the tandem to share the role — both backs are experienced and bring different running styles onto the field, and both have the talent to continue Mullen’s trend of 1,000 yard rushers at Mississippi State.

However, this year there’s a problem that Mullen has never had to compensate for to this degree: Mississippi State’s offensive line is as depleted as its been during the Mullen era, and that could create much bigger problems in the ground game than the loss of Robinson.

The Bulldogs lost their top three offensive linemen off last year’s team in tackle Blaine Clausell, guard Ben Beckwith and center Dillon Day, not to mention fellow offensive tackle Damien Robinson, who missed his entire senior year with a torn ACL suffered during training camp. Robinson was expected to start at right tackle opposite Clausell.

So Mississippi State now turns the page to 2015 with just one starting offensive lineman left from opening day of training camp last summer. No matter what Holloway and Shumpert do this fall, if the four new linemen on the field can’t figure out their roles in a hurry, the run game is poised to suffer.

Guard Justin Malone is the only player returning this season who was listed with the first team on last year’s depth chart to open training camp. Justin Senior, a rising junior who spent the year starting at right tackle in Damien Robinson’s place, will also provide some experience up front.

But fellow tackles Rufus Warren and Cole Carter as well as guards Jamaal Clayborn and Devon Desper boast zero combined starts between the four of them. Worse yet, last year’s backup center, Archie Muniz, was also a senior who has since graduated.

And while the Bulldogs did address the offensive line during the past recruiting cycle, adding players like four-star early enrollee offensive tackle Martinas Rankin and three-star center Darryl Williams, those players also lack experience and would be more developmental pieces in the lineup than consistent contributors.

So to recap, the Bulldogs are poised to replace three starters up front alongside Malone and Senior, and none of those players have experience starting at the SEC level. Until proven otherwise, the word to describe the look of Mississippi State’s returning offensive line is “patchwork.” That’s not exactly a compliment.

Holloway and Shumpert’s experience in Mullen’s offense will help compensate for the line somewhat, as will their complementary “thunder and lightning” running styles. But if the Mississippi State run game fails in 2015, don’t go looking to blame the backs.

Instead look to the offensive line, which is not so much bad as it is inexperienced. Nevertheless, if the MSU ground game experiences a severe regression in 2015, you know where to look.