Not only did Adrian Peterson return to football eight months after destroying his knee, he went on to have the second-best single-season rushing effort in NFL history. By the time 2012 was in the books, Peterson had rushed for 2,097 yards, nine yards shy of Eric Dickerson's all-time mark.
But the Vikings' other-worldly running back isn't surprised by the whispers that he used human growth hormone to regain his Pro Bowl form in such a short time. He also isn't offended by the accusations.
"Seriously. Especially with the amount of work I put in," Peterson told USA Today recently. "Guys say that to me, or if I hear someone saying that -- it makes me feel good. When you know you don't do it, and someone's saying you do, you're like, 'Wow. They think I'm on HGH? I'm doing that good? Well, hoo! Thank you, Jesus!' It's a compliment. I don't get mad about it at all."
The Vikings' running back said he doesn't know any players who use HGH but he's "sure" it happens.
"People are trying to get the edge," Peterson said. "The reality of it is, people are trying to provide for their families. People are trying to keep their spot on the rosters. If it's something they can use that's not going to show up, they're going to use it."
Peterson, who wants to break Emmitt Smith's career rushing record by 2017, answered similar questions at the start of training camp, telling the Associated Press that he welcomes HGH testing.
''I can't wait until they draw my blood,'' he said in late July. "To be honest with you, I've been hoping they did this a long time ago, you know, evening out the playing field and make guys be honest and truthful to themselves. I'm all natural. I work hard. This right here, it's a test for me personally, that I know that, 'Hey, I'm clean as a whistle.'"
Steelers defensive end Brett Keisel agrees.
"I would like for us to be tested right now," Keisel said via USA Today. "Like Adrian Peterson said, we all should be held to the same standard. If guys are cheating, it should be brought to the forefront.
"I honestly don't know what percentage of players are doing it," Keisel continued. "Sometimes, you feel like someone is. You don't know what people's work ethic is. You don't know how hard guys train. Some guys are just freaks of nature. … That's why it would be great to get the testing, so they'll have an idea of what's going on.''