NFL's most important returning players

49ers linebacker Aldon Smith enrolled in a substance-abuse treatment center. Cary Edmondson/US Presswire

By rule, NFL players have been practicing less frequently and less physically the past couple of years. They’re also suffering injuries more often. It’s an issue the league will have to address if the carnage continues.

Not all the injury news is bad. Percy Harvin, Russell Okung, Randall Cobb, Michael Crabtree and Dennis Pitta are among the key players on the verge of returning to their teams just in time for a playoff push. But the player atop our list of marquee returners wasn't injured at all. He recently returned from the non-football injury list and should see his playing time increase dramatically Sunday.

With input from an NFL personnel director, an assistant coach and four players with Pro Bowls on their résumés, we kick off Week 12 by ranking the top six returning players by greatest expected impact. There was a disagreement over Harvin in particular, for reasons we'll get into below. From there, we'll fulfill a request to investigate how Peyton Manning and other quarterbacks have fared against the best defenses.