Adrian Peterson and Chris Johnson are selfish tailbacks in a quarterback’s league. While the league’s elite offenses are relying on symbiotic relationships between quarterbacks and receivers to lay siege to defenses by air, they keep hogging all of the team yardage for themselves. They also steal yards after contact and have the nerve to ask for more carries and yardage. How rude.

After enduring a few rocky seasons since rushing for 2,006 yards four years ago, Johnson defiantly made his annual 2,000-yard proclamation on Tuesday.

“Every year coming in, I have a goal, but every time I say what my goal is, everybody thinks I am a selfish player and not a team player,” Johnson said Tuesday in The Tennessean. “Every year, I want to rush for 2,000 yards, and I feel like if we are doing what is right and we are making plays on Sunday, if I get to that yardage, I feel like we can be a playoff team and hopefully win the Super Bowl.”

Last month, Peterson scoffed at the subpar feat of attaining 2,000 yards.

“I’ve got my bar set for 2,500. If I could go up to that, the record is shattered,” Peterson said in a Sports Illustrated interview.

That’s not all they have in common. The fates of the Vikings and Titans don’t rest on the legs of their respective world-class running backs. Barring injury, Johnson and Peterson are sure things for 2013. Christian Ponder and Jake Locker are the variables in these winning equations. They can run for 3,000 yards, but unless their respective quarterbacks can lower their carry totals, both are destined to live out a fate much like Barry Sanders’.

Sanders’ career is proof that yards can’t bring you happiness. Sanders was more difficult to catch than a gnat in the open field, but playoff prosperity was just as elusive throughout his career. He experienced arguably the largest disparity between individual and team success in the annals of NFL history because the Detroit Lions couldn't pair him with a . The list of quarterbacks who were tasked with the arduous duty of handing off to Sanders on first and second down or third and shorts includes Rodney Peete, Bob Gagliano, Andre Ware, Dave Krieg, Charlie Batch and Scott Mitchell.

Peterson and Johnson are running-back royalty, but that’s not saying much. Running backs sacrifice their bodies to grind for extra yardage in pursuit of modest riches and get discarded at the first sign of decline. The cat-quick Johnson has avoided major injury, but speed is the first thing to go. Peterson’s already caught a glimpse of the realities of his mortality, spending an arduous 2012 offseason rehabbing what could have been a career-crippling knee injury.

Conversely, Ponder and Locker are paupers in a land of quarterback privilege. Both embarked on NFL careers as top-15 picks, but have fallen behind the development of 2011 peers such as Colin Kaepernick, Andy Dalton and Cam Newton. 

The most impressive aspect of Peterson’s 2012 record wasn’t his Wolverine-like healing ability; it was his ability to “monster truck rally” over defenses that didn’t respect the Vikings’ passing prowess. Perhaps this is why the Vikes signed Greg Jennings with the expectation of watching him develop a rapport with Ponder and open up the offense.

Going back to college, the knock on Locker has been his faulty mechanics. It’s fitting for a quarterback who burst onto the collegiate scene as the “West Coast Tebow.” The Titans took a flyer on uber-athletic wide receiver Justin Hunter in the draft, but to take advantage of Locker’s mobility, the Titans have installed a clone of the pistol read option-based offenses that have spread like SARS throughout the league.

Fellow 2011 draft pick Blaine Gabbert’s time may have already run out in Jacksonville, but Ponder and Locker have another opportunity to lock down their starting jobs. It sounds harsh, but the clock is ticking on the primes of Johnson and Peterson’s careers and it shouldn’t be wasted. It may seem unfair, but in this immediate gratification age, this should be “put up or shut up” time for Ponder and Locker.