If you're looking for an article that is attempting to argue that Adrian Peterson shouldn't be a member of the Vikings because of his child abuse scandal, then look elsewhere. This is not that kind of article. Instead, I'm going to argue that Adrian Peterson should not be a member of the Minnesota Vikings in the 2015 season and beyond for purely football reasons.

The first reason Adrian Peterson should not be a member of the Vikings going forward is because he will turn 30-years old in a few months. There have been many studies done about the effects of aging on athletes, but I like this one in particular from 2012 as it is focused on running backs. You should read the entire article, because there is a lot of great information there, but the conclusion was this:

There is no one age when all running backs drop off, or even an age where the majority of running backs drop off. That said, by the end of their age 29 season (or, if you prefer, by the time they hit 30), half of the running backs in this study were essentially washed up. Most had gradual declines, or a down season followed by a bounce-back year and then another decline, rather than a sudden collision with a mythical wall. But at age 31 or later, 42% of the running backs had at least one solid season.

In other words, from this moment forward any team that plays Adrian Peterson will be getting a version of him that is somehow lesser than the one they got the year before. If history is any guide, Peterson has about a 50-50 chance to continue his elite level of production in 2015, due simply to the fact that he is aging (and there is no miracle drug that can prevent aging). Some may point to his historically fast recovery time after the ACL as evidence that maybe Peterson can do better than half of his colleagues, or point to his incredible off-season work ethic and training regimens as another thing that may help him beat the odds. But one could probably make similar arguments about many of the other running backs from that same study, and not all of them performed at a high level past the age of 30.

An even more compelling argument than age for running back decline is one of "usage" or career touches. Over at Pro Football Focus, a similar study of running backs was completed in 2012 that determined 3,000 career touches is the magic number for running back expiration dates. Adrian Peterson has 2,054 carries, 208 receptions and 17 returns for a total of 2,279 touches. Ignoring this past season, Peterson has averaged 322 touches per season through his first 7 years in the NFL (which includes his shortened 2011 season and rookie year where he split time with Chester Taylor), which would imply that Peterson has, at best, 2-3 years of production left before he hits the magical 3,000 touch mark. In the end, whether it is age or usage that catches up with him, retaining Peterson in 2015 and beyond is essentially a roll of the dice in terms of not knowing when his skills will diminish, or by how much. It's not a question of if Peterson's skill will diminish, but a question of when. And history is telling us that his time is coming to end sooner rather than later.

The second reason Adrian Peterson should not be a member of the Vikings going forward is because his decline may actually be happening already. Below are two graphs showing some of Peterson's rushing statistics on a per season basis: attempts per game and yards per game, and yards per carry average. All three statistics show an overall descending trend line. While there are lots of ups and downs through the course of Peterson's 8-year career, including a historically great 2012 season, his trend line is still pointing downwards overall (imagine how much worse it would be without that 2012 season included).

The first thing to notice is that Peterson's usage trend line as shown as attempts per game average is upwards! On a per-game average basis, the Vikings have been increasing Peterson's usage from one year to the next, overall. But his efficiency numbers are showing a gradual decline over his 8-year career. Granted, his 2014 season is included in the trend lines with only 1 game's worth of production, but even still the point is simply this: Adrian Peterson's best years are behind him at this point. If there is any trend that seems most likely for Peterson's production going forward, it is a downward trend.

The third reason Adrian Peterson should not be a member of the Vikings going forward is that his contract is astronomical and his salary cap figures are way out of proportion for the level of production he provides the Vikings relative to the rest of the NFL. Here is a list of the top 20 cap figures for all running backs in 2015, courtesy of Spotrac. Is there one (or two) that don't look like the others?

While there is certainly a case to be made that elite running backs deserve to be paid a premium, that premium for most backs in the NFL is between $5-8 million in 2015. Peterson will count nearly twice that against the Vikings cap in 2015 if he remains with the team on his current contract. Fortunately for the Vikings, he is no longer due anymore guaranteed money and the team will only incur $2.4 million in dead money against the cap if he is cut (representing a savings of $13 million in cap space). In 2016 and beyond, Peterson would count nothing against the cap if he were cut. When the Vikings extended Peterson's contract in 2011 they were clearly hedging their bets that Peterson would decline at least starting in 2016 if not even in 2015, as they would be able to cut him free of cap penalty in the final two years of his deal. Most NFL players never reach those end-weighted, non-guaranteed years of their massive contracts.

All that said, the Vikings do have a potentially valuable commodity in Adrian Peterson and simply cutting him in the off-season would represent a certain loss of value to the team. He's a former MVP, all-Pro running back that, despite the scandal and age, should still fetch some draft pick compensation on the open market. If I were running the Vikings front office, I would be entertaining any and all trade offers for Adrian Peterson. A first round draft pick may be out of the question, but getting a mid-round pick in trade would still free up cap space and get something in return for Peterson.

And the fourth and final reason that the Vikings should move on from Adrian Peterson in 2015 and beyond, is because they have already adequately replaced him, and could do even better with another competent acquisition in the off-season. This may come as a shock to some, but if you combine all of the rushing production that the Vikings achieved without Adrian Peterson, that imaginary player would have ended the year with the following stat line: 392 carries, 1,729 yards, 12 touchdowns and 4.4 yards per carry. Now granted, even in Peterson's historic 2012 season he did not get all of the carries. If we ignore 2014, over the course of Peterson's first 7 years in the league, he averaged about 62% of the total team carries. But even taking 62% of that 2014 team production without Peterson, that rounds up to: 243 carries, 1,072 yards, 7 touchdowns and 4.4 yards per carry. Again, ignoring 2014 for the moment, Peterson's 7-year career average (which includes the shortened 2011 season and his historically great 2012) is: 290 carries, 1,445 yards and 4.9 yards per carry. While that career average is certainly better than the 62% 2014 team average, I would argue that it's not $15 million worth of cap space better. Peterson has nearly 400 more rushing yards, but he also has nearly 50 more carries. His per carry average is only a half-yard better than the rest of the team on average. As I've shown above, Peterson's statistical trend lines are pointing downwards. So, the logical expectation for Peterson's production in 2015 and beyond is below his career average marks.

Furthermore, imagine if we replaced Matt Asiata and Ben Tate's production in 2014 (both averaged 3.5 and 2.9 yards per carry) with a more competent option, say a 2015 draft pick or free agent option who could average 4.0 yards per carry instead? If you swap out their poor production with that imaginary 4.0 YPC runner, that would add about 100 total yards to the production and bump up the 2014 YPC team average from 4.4 to 4.8. If you've followed that so far, that's only 0.1 yards per carry less than Peterson's career average (or essentially what we could expect in decline from Peterson in 2015). Granted, that is a hypothetical on top of another hypothetical, but the point of the exercise is to show that getting a running back this off-season that is a little better than Matt Asiata and pairing him with Jerick Mckinnon in 2015 would probably just about equal what a 30-year old Adrian Peterson would do, and as pointed out earlier, at a fraction of the cost.

And the good news is that there are going to be a lot of running back options available this offseason that the Vikings could potentially go after. Below is a list of some of the better free agents and top draft prospects available.

Running Backs Options for 2015 Player 2014 Team 2015 Status Age Ryan Mathews San Diego Free Agent 27 Knowshon Moreno Miami Free Agent 27 Mark Ingram New Orleans Free Agent 25 DeMarco Murray Dallas Free Agent 26 Shane Vereen New England Free Agent 25 Stevan Ridley New England Free Agent 25 Melvin Gordon College 1st Round Grade 21 Todd Gurley College 1st Round Grade 21 Ameer Abdullah College 2nd Round Grade 21 Tevin Coleman College 2nd Round Grade 21 Duke Johnson College 2nd Round Grade 21 T.J. Yeldon College 2nd Round Grade 21 Mike Davis College 2nd Round Grade 21 Jay Ajayi College 2nd Round Grade 21 Javorius Allen College 2nd Round Grade 21

While none of these replacement options will probably perform like Adrian Peterson in his prime, I would argue that they are just as likely to perform as well as Matt Asiata did this year, with immense upside to do even better. And as I mentioned above, pairing a runner that is better than Asiata with Mckinnon has a strong likelihood to perform as well as a 30-year old Adrian Peterson (who has essentially been out of football for a year) in 2015 and most assuredly beyond. At the end of the day these four reasons for not keeping Adrian Peterson: age, already in decline, salary cap number and the fact that he was already adequately replaced in 2014, would outweigh any potential gains for keeping Peterson. What positives are there to keeping Adrian Peterson, from a pure football standpoint and for a $15 million cap hit? Is he the face of the franchise? Does his performance sell tickets? Can he single-handedly win games for the Vikings? I'm not sure the answer to all of those questions is yes anymore, and to me at least, there are far more compelling reasons to move on from Adrian Peterson than there are for keeping him.

I asked some of the other front page writers to come up with some compelling reasons to keep Adrian Peterson next season and beyond, and the best they could come up with was the following:

1. Matt Asiata isn't an adequate replacement.

Agreed. But this is more of an argument for not keeping Matt Asiata, than it is about keeping Adrian Peterson around. If you replaced Matt Asiata with one of the options above and paired that running back with Mckinnon, it would seem like a pretty good "running back by committee" replacement of Adrian Peterson.

2. We don't want to get Bridgewater killed.

Now granted, defenses respect Adrian Peterson as a threat at running back (or at least, they used to) and would frequently stack 8 or 9 men in the box to stop the run. Bridgewater has rarely had the luxury of increased 8-9 man fronts so far in his career. So in that respect, there could be something to this concern. But if we're talking about pass blocking from the running back position, then this argument loses a lot of steam. Adrian Peterson was not graded favorably by Pro Football Focus in blocking recently getting a +0.1 and -0.9 grade in the 2013 and 2012 seasons, both grades ranked in the bottom half of starting running backs. In fact, Matt Asiata is probably the best pass blocking running back on the team as PFF graded him at +0.9 this year, ranked 20th out of 57 running backs in the NFL.

3. Mckinnon is small and couldn't stay on the field in 2015.

While size is generally a fan's worry about getting injured, it is not statistically relevant. Some of the best predictor's of an NFL player's chances of injury are age, the position they play and history of injury. Mckinnon's injury that sidelined his 2014 season wasn't even from an on-field incident. He injured his back in the training room, lifting weights. Mckinnon has just as much chance of being injured as any other running back on the Vikings. So, this isn't a concern for me. If anything, there should be greater concern about Peterson's ability to stay on the field in 2015 with his age, and the fact that he's already dealt with a ton of his injuries in his career dating back to college and the fact that he plays the running back position. And like the first point, this argument isn't so much about keeping Peterson as it is about voicing concern about replacement options already on the roster.

There were many other "fan oriented" arguments made about wanting to be able to wear Peterson jerseys, not wanting to see Peterson play for another team, and wanting to experience a redemption story for a beloved player. But none of those arguments holds any water from a pure football perspective. At the end of the day the argument for keeping Peterson has to boil down to an expectation that he will continue to perform at the same high level that he has during his first 8 years in the league. There would appear to be a far greater chance that he is due for a decline in production than he is to equal or exceed his career numbers. And when you factor in his astronomical cap number, it makes the most sense to find a replacement for Peterson via free agency or the draft at a fraction of the cost. Freeing up $13 million in cap space would allow the Vikings to patch up the last few holes on defense and shore up the offensive line in free agency, or even make a run at a wide receiver (not to mention have cash on hand to extend elite players that will become free agents in 2016 like Harrison Smith, Rhett Ellison and Blair Walsh). There are just so many good reasons to move on from Adrian Peterson, if not in 2015 than surely in 2016 when his dead money number is $0. But like Jared Allen and countless others that the Vikings arguably waited too long to say goodbye to and then got nothing in return, the Vikings should aggressively try to trade Adrian Peterson to the highest bidder this off-season. As Mike Zimmer said during a recent press conference, this is now Teddy Bridgewater's team. Let the Adrian Peterson era end and a new chapter begin.