To no one's surprise, Miami Dolphins running back Arian Foster is once again on the injury report, lasting just five quarters in the 2016 season before pulling up lame on Sunday with a groin injury.

If that injury sounds familiar, it's because it should; Foster missed much of the 2015 season after tearing the groin muscle from the bone during his first practice. Ouch. He also missed two games during the 2014 season with a groin injury.

Of course, the inconsistency and immaturity of the backs behind him on the depth chart were the reasons Foster was signed by the Dolphins late in mid-July, so predicting who stands to benefit in the event of a prolonged absence is difficult.

But with a intriguing matchup against the Cleveland Browns on Sunday and knowing how brittle Foster has been over the course of his career, identifying if any value exists in this backfield is a worthwhile task. So what can we make of the remaining backs on the depth chart?

The Case for Jay Ajayi

Jay Ajayi was widely considered to be a top-three talent in the 2015 NFL draft, behind only Todd Gurley and Melvin Gordon. He was a creative and powerful between-the-tackles runner with the speed to get to the edge and an exceptional pass-catcher out of the backfield (50 receptions as a junior), profiling as a true workhorse back. Similar to Bryce Brown, Ajayi is undisciplined as a runner, with an eye for open space that often gets him into trouble. But in the open field, Ajayi is a Marshawn Lynch type of runner, violent and aggressive with the speed and power to be a game-changing weapon for the Dolphins.

But reports about a degenerative knee condition surfaced in the spring, causing his draft stock to plummet until he was finally selected in the fifth round by the Dolphins. The knee injury is expected to limit the length of his NFL career, and while injuries have limited him at the start of his career, none have been related to that knee.

Unfortunately, the NFL hasn't been kind to Ajayi, with pass protection issues and inconsistency as a receiver leading many (his coaches included) to view him as a disappointment. He reportedly showed immaturity in regards to his demotion in favor of Foster, causing new head coach Adam Gase to leave Ajayi at the airport in Miami while the team flew to Seattle for Week 1.

In Week 2, the Dolphins found themselves trailing 21-0 when they lost Foster to injury just minutes into the second quarter, and he never had the game script needed to provide Ajayi with the chance to run the ball. The sophomore back had just 5 carries for 14 yards but did chip in 4 receptions for 31 yards out of the backfield. Most notably, however, is that Adam Gase praised his work in pass protection, perhaps the most significant hurdle to Ajayi's attempt to reclaim this backfield.

In terms of our Net Expected Points (NEP) metrics, Ajayi was passable during his rookie season, and his -0.01 Rushing NEP per rush score was close to backs like Bilal Powell (-0.00) and Charles Sims (-0.01). For those keeping score, that's much better than what rookie sensation Ezekiel Elliott has produced (-0.14) on a similar number of carries to start his career. That's not to say Ajayi is a better player but simply to point out that making snap judgements about his overall talent based on a limited workload is dangerous (see: Freeman, Devonta).

Against a soft Cleveland run defense this Sunday, Ajayi has the chance to prove to this coaching staff and his team that he deserves a major role in this offense. And given his background, talent, and the injury history of Arian Foster, I'm intrigued by the possibility.

The Case for the Field

Of course, Ajayi and Foster aren't the only two backs for the Dolphins. In fact, they have a deep bench at the position featuring rookie third-round pick Kenyan Drake, Los Angeles Rams castoff Isaiah Pead, and the often forgotten Damien Williams. Do any of these backs have a reasonable chance to unseat Ajayi for the backup role?

While Pead had moments of success during the preseason and Williams has some ability, both have struggled to make much of an impression during their careers. They do offer some change-of-pace ability but aren't likely to see the field if either Ajayi or Drake can prove to be competent.

But while Ajayi is the draft pick of a former Miami regime, Drake was hand-selected by this current staff, who surprised many by selecting the former Alabama back so high in the draft. While the young back is an intriguing blend of size and explosive speed, he was always a backup in college behind talents such as Eddie Lacy, T.J. Yeldon, and Heisman winner Derrick Henry. Yet it was Drake who scored the Dolphins' only rushing touchdown on Sunday, demonstrating his ability to get to the corner on a seven-yard run.

That said, Drake was extremely inconsistent as a collegian, dropping 5 passes with 44 receptions and earning the reputation as a poor pass blocker. Those trends continued during the Senior Bowl, perhaps giving a glimpse as to why Drake was primarily a gadget player at Alabama instead of a featured runner.

While it's certainly a possibility that the young back has been coached up on those issues during his time with Miami, he won't stay on the field long if he can't keep Ryan Tannehill upright.

The Verdict

If Sunday is any indication, Ajayi will have the first chance to crack the lineup, and he out-touched Drake nine to four during the remainder of the game. Of course, if we are basing everything on Sunday, then no back will have much of an opportunity if the team continues to struggle to block and defend like they did against the New England Patriots.

The team's offensive line seems improved in pass protection but also features four former left tackles across the unit, and that seems to be affecting their ability to gain a strong push in the running game. Still, if they can grow as a unit, there is enough talent to provide opportunities for either Ajayi or Drake to make plays.

If I have to bet on one guy not named Arian Foster, I'm placing my chips on Ajayi to have the most value. It's difficult to forget how much he carried his Boise State team during his career, scoring 32 touchdowns and totaling 2,358 yards in his final season alone. He was a feature back in every way imaginable, and the hope here is that his Week 1 benching was the wake-up-call he needed. While Drake certainly has the explosiveness necessary to make his mark, his inexperience as a blocker and with the playbook might limit the opportunity he has to gain a significant workload.

What I refuse to bet on, however, is a healthy season for Arian Foster.