Fred Jackson enjoyed dominating in Buffalo’s backfield last year when he was healthy, but he didn’t enjoy his paycheck. The Bills knew he deserved a better number on that piece of paper, but dealing with Jackson is a matter of balance, as it is for every team trying to keep its top running back happy. There’s a need to acknowledge the talent level and consistent offensive contribution, but that’s weighed heavily against the lack of longevity for the average RB’s career.

Bills management was understandably apprehensive regarding Jackson, who was set to enter the final season of a four-year contract while making $1.995 million. Now that’s changed, and Buddy Nix has finally decided to pay the man.

The Bills officially announced a two-year extension for Jackson in a press conference Monday afternoon that’s reportedly worth $8.7 million, with a $3 million signing bonus. Combined with what’s left on his current contract, Jackson will make roughly $3.6 million annually over the next three years. Despite his success during the 2011 season prior to his injury, that’s the going rate for a 31-year-old running back. Since last august the bills have now extended the contracts of Jackson, Ryan Fitzpatrick, Kyle Williams, and Stevie Johnson.

Jackson isn’t your normal 31-year-old running back, though, as prior to last year the pounding he absorbed was limited by platoon situations. He still hasn’t had a 300-carry season, or even a 250-carry season, both marks he was easily on pace to break last year through 10 games when was among the league’s leading rushers with 934 yards before he suffered a fractured fibula.

The minimal term and minimal value is ideal for both the team and player, as the Bills control their risk, while Jackson ensures that his career will finish where it started. It isn’t ideal for C.J. Spiller, the Bills’ other electrifying running back who’s flashed considerable skill as a receiver out of the backfield, but would still like to be put into more situations that properly reflect his job title.

Despite missing seven games, Jackson accounted for nearly a quarter of Buffalo’s offensive yardage with his six 100-yard rushing games, and he tacked on 442 receiving yards for a total of 1,372 all-purpose yards and six touchdowns. He was the Bills’ offense during those first 10 weeks, but Spiller still averaged 5.2 yards per carry, and he’s become a versatile weapon who’s often forced to sit stagnant on the sidelines when Jackson is healthy.

Chan Gailey has spoken positively about a potential split and having a highly effective two-headed monster, but that’s likely lip service. If Jackson gets rolling again and is averaging around 100 rushing yards per game as he was last fall, he’ll naturally be the featured back, and Spiller will watch and get five or fewer carries.

When that happens, Spiller will continue to be a wasted draft pick, a legacy that will only grow with Jackson now under contract until he’s 34. Spiller will be 27 when Jackson finally fades off into the NFL RB wasteland, and the former Clemson star could be well on his way to that same inevitable decline as the death age of 30 approaches. His carries and by extension the punishment he has to sustain will be limited, so Spiller could become another late bloomer just like Jackson.

But Jackson is a unique, nearly unprecedented case, so banking on Spiller’s body to respond the same way over time is unwise.