The inevitable RG3 - Adrian Peterson talk

So you might have noticed that Washington Redskins quarterback Robert Griffin III tweeted that he has been cleared to practice when the team opens training camp, less than eight months after tearing two knee ligaments in his right knee. Because the comparisons are inevitable, I thought we should establish some similarities and differences between Griffin's recovery and that of Minnesota Vikings tailback Adrian Peterson.

We should note at the outset that Peterson and Griffin both tore their ACLs, but Peterson's second tear was to the MCL while Griffin's was to the LCL. Another important difference: It's relatively easy to protect a quarterback from contact in practice with a red jersey and quick whistles. The same can not be said for a running back.

With that said, a total of 231 days passed between Peterson's injury on Dec. 24, 2011 and his first practice on Aug. 12, 2012. Peterson spent the next two weeks participating in a limited portion of practice before coaches cleared defenders to hit his upper body during drills on Aug. 27. 2012.

Peterson didn't play in the preseason, so his Week 1 start against the Jacksonville Jaguars -- 260 days after the injury -- served as his first full-contact football activity.

Griffin suffered his injury on Jan. 6, 2013. That means 196 days passed between the injury and being cleared to practice. He will reportedly participate in individual and some 7-on-7 drills at the beginning of camp but will be held out of full-speed team drills.

We should be careful about turning these timetables into a competition. I hope everyone would recognize the physical demands on a running back are more significant than for a quarterback, especially in training camp and even in the preseason.

Just the same, in the larger picture, Griffin's recovery might force us to tweak how we view Peterson's return last season. Assuming Griffin has no setbacks, he will join Peterson in essentially recovering from a major knee injury during a single offseason. That will make Peterson a rehabilitation trailblazer rather than an anomaly -- which is no less an accomplishment, by the way.

Griffin's next step, however, might be more difficult than what he has already achieved. To continue matching Peterson's big-picture accomplishment, Griffin must return at an elevated level of performance. Peterson had one of the best seasons by a running back in NFL history in 2012. The standard has been set for Griffin and all others who follow that path.