On the one hand, Peterson returned from two torn ligaments in his left knee quicker and better than anyone in this universe thought possible.
Peterson threatens the all-time single season rushing record. Manning captains arguably the best team in the NFL.
Peterson has had the best season of his already-legendary career. Manning flawlessly converted a Tebow-oriented offense into a Manning-oriented offense.
Both suffered potentially career-ending injuries. Yet both stories now sit among the best and most impressive comeback tales ever.
Yet which is more impressive?
Grades and Case for Adrian Peterson
Injury Severity: A
The video of Peterson' knee injury is the kind seen in nightmares. As can be seen, the knee of his planted left leg buckles under the weight of Washington Redskins safety DeJon Gomes, and Peterson must be carted off the field.
Peterson tore his anterior cruciate ligament (ACL) and medial collateral ligament (MCL) on the play. Without an intact ACL and MCL, a knee becomes unstable, and balancing, changing directions and cutting are essentially impossible.
Surgery Complexity: B
ACL repair surgery involves taking a small piece of the athlete's hamstring muscle tendon or patellar tendon (the part of the knee that a doctor hits with a reflex hammer) and using it to replace the torn ACL.
To do so, an orthopaedic surgeon uses small incisions in the knee to insert a tiny camera as well as other instruments into the knee joint. After removing the piece of muscle tendon, called a "graft," he or she attaches it to the bottom of the femur (thigh bone) and top of the tibia (shin bone). The graft then functions as a replacement ACL.
Rehabilitation Regimen Difficulty: A
ACL tear rehabilitation requires months of dedication, considerable daily effort and intense determination and will power. The simplest physical tasks are made difficult, if not impossible, by an ACL tear. An athlete must progress excruciatingly slowly from difficulties with merely walking all the way to sprinting and cutting, all while the ACL graft is cemented into place by the body.
Rate of Progress Through Rehabilitation: A+
Peterson's rate of progression from injury to starting Week 1 for the Vikings' 2012 season is mind-boggling. Most ACL injuries require seven to nine months just to return to normal activity. To return to NFL-caliber play, one would think it would take even longer.
Games Missed: C
As incredible as it sounds, Peterson sat for just one regular season game due to his injury. Of course, he also missed considerable training and practice time during the offseason. However, his injury sidelined him for only one week of so-called "game-time speed."
Performance During 2012 NFL Season: A+
I'll leave it at this: Peterson may break the all-time single season rushing record approximately one year after tearing two ligaments in his knee.
I still can't believe that I just wrote that sentence.
Grades and Case for Peyton Manning
Injury Severity: A-
Manning underwent spinal fusion surgery. That means that one of the cushions between the vertebrae in his neck, known as the intervertebral discs, slipped out of place and was pressing on the nerves in his neck as they left the spinal cord.
The nerves in the neck control the strength and sensation of the arms. Compression from a disc leads to pain, weakness and numbness in the neck and arm. If the compression is severe enough, permanent damage and disability results.
Surgery Complexity: A+
The technical term for Manning's fourth and final surgery is a "single-level anterior cervical discectomy and fusion."
In other words, a surgeon made incisions in the front of Manning's neck, made his or her way around muscles, tissues and blood vessels to the spine, removed the slipped disc and fused together the vertebrae on either side of the removed disc using metal screws and frames.
Some surgeons also place pieces of bone into the gap left by the removed disc that the body will then fuse into place.
I have personally observed and assisted on three anterior discectomy and fusion surgeries, and yes, they are just as complicated as they sound.
Rehabilitation Regimen Complexity: B
Rehabilitation following a cervical discectomy involves strength training and range of motion exercises of the head, neck and arm.
Without a doubt, Manning's success serves as a testament to the dedication and determination of both Manning and his physical therapy team. However, Peterson gets the edge due to the shear amount of work required to return to his previous level.
Rate of Progress Through Rehabilitation: C
Manning sat out the entire 2011 season following his surgery.
That should not surprise anyone. After all, he needed to progress from not being able to throw a football all the way to returning to the field as a starter.
Manning's grade of a "C" is more representative of Peterson's unbelievable success rather than any failure on Manning's part.
Games Missed: A+
Manning missed an entire season of competitive play. Without missing a beat, he then engineered a seamless 180-degree shift of offensive schemes in Denver. As a result, the Broncos may be the Super Bowl favorite. Need I say more?
Performance During 2012 NFL Season: A
Peyton's play this season has been as good as ever. That said, Peterson's play has been better than ever, giving him a slight advantage here.
Overall Grades (Winner: Adrian Peterson)
Which injury comeback story is the most impressive?
Adrian Peterson: A++
Peyton Manning: A+
This was as close as the vote for the 2009 Heisman, and the comebacks of both Peterson and Manning are, without a doubt, among the most amazing injury comeback stories in sports history.
Given the fact that Manning missed the 2011 season, he will likely win Comeback Player of the Year and possibly MVP.
However, when both medical and on-field accomplishments are taken into account, Peterson's story is ever-so-slightly more impressive than Manning's.
Yet in the end, isn't all that matters is that we sit back and enjoy the show?
Dave Siebert is a medical/injury Featured Columnist for Bleacher Report who will graduate from medical school in June, 2013. He plans to specialize in both Family Medicine and Primary Care (non-operative) Sports Medicine. Injury and anatomical information discussed above is based on his own knowledge and experience.