In his 16th game of the 2011 season, the best running back of this generation was finishing off a three-yard run when he felt three pops in his left knee. It was a telltale sign, dispiriting to any aware athlete: a torn anterior cruciate ligaments (ACL).
X-rays brought worse news: torn medial collateral ligaments, too. With diligent rehabilitation and a dose of luck, doctors concluded, Adrian Peterson might answer the bell for the Minnesota Vikings' first game this year, although likely below prime condition.
Brilliant athletes are infused with optimism, and Peterson was bent on resuming quickly, with no sacrifice in the ability to cut or power through a tackler.
"I know it might sound crazy," he recently told the New York Times, "but that was my mindset."
Anyone who anticipated Peterson's astounding output in the comeback year would have been judged as out of his mind.
Peterson has amassed the eighth most rushing yards ever, with today's game against Green Bay an opportunity to rise in the rankings.
The gold standard for ball carriers - Eric Dickerson's 2,105 yards in 1984 - appears beyond reach, with Peterson needing 208 to exceed it. He did pile up 210 yards earlier this month against the Packers, but a fresh, less severe set of injuries (abdomen, groin) has slowed him.
A more reasonable target is 102 yards, which would crown Peterson as the sixth man to top 2,000 yards. A dissection of Peterson's total reveals a more impressive sub-statistic: yards gained after initial contact with a defender. The amount, 932, represents nearly half.
Almost as impressive is the few runs for negative yardage, which his coach, Leslie Frazier, attributes to greater patience as a partial result of the injury.
"He [returned] as a better student of the game," Frazier told ESPN. "That has to do with going through such an intense rehab."
Peterson was not exactly patient during recovery. The stitches were still evident in the spring when his Vikings teammates were stunned that he joined the receivers in sprints - and beat them.
"It's mental ... my willpower, my determination," he said. "I grind hard. When you want to be great - and, in my mind, I want to be the greatest that ever played - you can't talk about it. You have to go out and work."
Peterson can interrupt a stretch of quarterbacks named Most Valuable Player that dates to 2006. Voters torn between the other primary candidates, Peyton Manning and Tom Brady, could opt for the guy who told Frazier on the first day of training camp that he was ready to roll.
"An ACL injury at any position can be career-ending," Frazier said, "so to see Adrian come back as a running back and play the way he's playing - to be the best again - is just amazing to watch."
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