Despite Lack of Use, C.J. Spiller's Absence Is Huge Blow to Bills Offense

It was a day full of mixed emotions for the Buffalo Bills. On one hand, they rallied in dramatic fashion, beating the Minnesota Vikings, 17-16, in front of their adoring fans. On the other side of the coin, they lost running backs Fred Jackson and C.J. Spiller to brutal injuries in the first half.

Jackson was the first go after suffering a groin injury. NFL Network's Ian Rapoport tweeted that the injury appears to be serious:

Replacing him in the backfield, Spiller tore off a splendid 52-yard run before he was dragged down, landing awkwardly on his shoulder in the process. Immediately you could tell he was in a world of pain.

After being carted off the field, ESPN's Adam Schefter and CBS Sports NFL Insider Jason La Canfora broke the news that Spiller broke his collarbone on the play:

It goes without saying that losing Jackson and Spiller is a somber revelation for this team. At 4-3, the Bills are currently second in the AFC East behind the New England Patriots. A big reason for that has been what these two backs have been able to do.

By Pro Football Focus' estimation (subscription required), prior to this week, Jackson was on the field for 60.9 percent of the team's offensive snaps, while Spiller was present for 36.9.

If Jackson is out for an extended period of time, that's monumental. The team counted on him to handle the bulk of work out of the backfield.

Despite his lack of use, Spiller's absence is big in its own right.

Of the two backs, Spiller has always been the home run threat. Two seasons ago under the guidance of then-head coach Chan Gailey, he rushed for 1,244 yards, caught 43 passes for an additional 459 yards and scored eight combined touchdowns.

He was an unstoppable force who turned out to be a perfect fit for Gailey's unique version of the spread offense. When Doug Marrone took over for Gailey prior to the 2013 season, Spiller's role started to change.

Marrone installed more of a "pro-style" offense that was a combined traditional running elements with forward-thinking schemes.

Spiller may have played second fiddle to Jackson, but the two combined to help the Bills finish as the second-best rushing team in 2013, averaging 144.2 yards per game.

More than anything else, the threat of Spiller is enough to warrant the attention of a defense. Like LeSean McCoy or even Jamaal Charles, he's always one nifty cut away from breaking out a long run.

Even in a limited role, he remained one of the most dangerous weapons present on the roster.

From a front office perspective, Spiller's injury now means that he won't be traded. It was Mike Florio of Pro Football Talk (h/t NBCSports.com) who talked about what the Bills could do with Spiller prior to his injury.

Tim Graham of The Buffalo News tweeted that despite the rumors, a source refuted those claims:

Odds are we won't find out what general manager Doug Whaley was actually thinking. In any case, Spiller's injury now means the front office has no chance of getting any value in return for him in a contract year.

The 4-3 Bills will now have to find a way to push forward without Spiller. One way they could replicate his role within the offense is by leaning on former Philadelphia Eagles halfback Bryce Brown.

The Bills acquired the zippy back during last offseason, but he's been a healthy scratch since he's arrived. Now that Spiller is gone, Brown is the obvious choice to step in and replace him.

It's now a distinct possibility that we won't see Spiller again in a Bills uniform. Based strictly on usage, it appeared like Marrone and offensive coordinator Nathaniel Hackett had already been phasing the 27-year-old out of the offense.

When you also consider that running backs have been viewed more as dime-a-dozen commodities, it doesn't make much sense financially to bring him back—even with his breakaway potential.

For Bills fans who loved the Clemson star, that reality is a tough pill to swallow.

Unless noted otherwise, all game scores and information come courtesy of ESPN.com.