How Will the Miami Dolphins Move on Without Knowshon Moreno?

The Miami Dolphins offense has struggled this season, and things aren't going to get any easier thanks to a key injury.

The Dolphins announced on Tuesday morning that running back Knowshon Moreno was placed on season-ending injured reserve with a torn ACL. 

Moreno signed a one-year contract with the Dolphins this offseason and had an operation on his knee that held him out for the start of training camp. He eventually got back onto the field but had been dealing with an elbow injury. Now, with his second knee injury in less than six months, he may have difficulty finding work in a league where running backs are as disposable as Kodak cameras.

Moreno was second on the team in carries (31) and rushing yards (148), and he had a healthy 4.8 yards per carry. Replacing him will not be easy. 

The good news for the Dolphins is that they have running back Lamar Miller to fill in the lead back role. The bad news is that the Dolphins no longer have a solid one-two punch in their backfield.

Player	Car	Yds	YPA	TD
Lamar Miller	63	330	5.2	3
Knowshon Moreno	31	148	4.8	1
Damien Williams	12	39	3.3	0
Daniel Thomas	7	50	7.7	0

Make no mistake—Miller has been effective for the Dolphins with Moreno out. 

In fact, Miller can do a lot of the same things Moreno does. He is effective as a one-cut back in a zone scheme, and he has solid long speed to take advantage when he gets out into the open field.

His explosive playmaking ability out of the backfield has already been evident at this early juncture of the season.

Where he does not fare well (and none of Miami's backs does) is in blitz protection. Their struggles protecting quarterback Ryan Tannehill last season were almost as prevalent as the offensive line. According to film review, Dolphins running backs combined to allow nine of the 58 sacks of Tannehill last season.

One problem has been that the Dolphins have not committed to the running game regularly enough this season, with only 27.4 rushing attempts per game (15th in the NFL) despite averaging 4.97 yards per rush attempt (third) this season. With less firepower in the backfield, the Dolphins may not be too eager to put the burden on their running game going forward.

Especially not if Daniel Thomas is the Dolphins' top backup option.

Yes, the same Daniel Thomas who averages 3.66 YPA in his career—which ranks 63rd out of 67 running backs with over 200 carries since 2011, according to Pro-Football-Reference.com.

Thomas did not make the team out of training camp. The Dolphins chose to go with younger options like Damien Williams and Orleans Darkwa, and they added former San Francisco 49ers running back LaMichael James to the practice squad.

Thomas does provide a different style of running, as a better fit for a between-the-tackles runner than anyone else the Dolphins have on the roster. Williams may be the choice if the Dolphins need a "scat back" who can fill the void left by Moreno.

The running game has been essential to the Dolphins' offensive success this season—even though they don't use it as much as they should. The Dolphins rushed for more than 150 yards in their two wins. Granted, any team would love to get that kind of production out of the running game, but with shaky performances out of their passing game, the Dolphins have needed that success in the running game to maintain a semblance of a competent offense.

Play type	Comp	Att	Cmp %	Rating
Play action	22	44	50	78.7
No play action	91	142	64.1	82.5

As mentioned previously, one of the major holes in the Dolphins backfield will be their pass protection. That group will have to step up to avoid some of the same pitfalls that plagued the offense last season. 

Beyond that, though, Tannehill has relied on the running game in other ways. This season, Tannehill has attempted 24.5 percent of his passes off a play-action fake—although, interestingly enough, his completion percentage is 14.1 points lower off play action than in a standard dropback without a fake, according to Pro Football Focus (subscription required).

In his career, Tannehill has played in 37 games and averages 34 attempts per game. In games where he attempts 34 or fewer passes, the Dolphins are 12-5 (.706). In games where he attempts 35 or more passes, the Dolphins are 5-15 (.250).

So, clearly, the Dolphins and Tannehill benefit from a balanced attack that does not put the full burden on the passing game; however, with the loss of one of the more dynamic backs they had in their backfield, their prospects in the running game may get worse before they get better.

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