If we knew for a fact every player would play 16 games, here's how I'd rank them: (I'm omitting players like Percy Harvin, Michael Crabtree and Dennis Pitta who are slated to miss most or all of the season already).

Quarterbacks

1. Aaron Rodgers
2. Cam Newton
3. Robert Griffin
4. Drew Brees
5. Peyton Manning
6. Andrew Luck
7. Tom Brady
8. Matt Ryan
9. Colin Kaepernick
10. Tony Romo
11. Russell Wilson
12. Matthew Stafford
13. Michael Vick
14. Eli Manning
15. Ben Roethlisberger
16. Alex Smith
17. Jay Cutler
18. Andy Dalton
19. Sam Bradford
20. EJ Manuel

Running Backs

1. Adrian Peterson
2. Jamaal Charles
3. C.J. Spiller
4. Doug Martin
5. Arian Foster
6. Trent Richardson
7. LeSean McCoy
8. Ray Rice
9. Marshawn Lynch
10. DeMarco Murray
11. Darren McFadden
12. Maurice Jones-Drew
13. Alfred Morris
14. Steven Jackson
15. Ahmad Bradshaw
16. Matt Forte
17. Lamar Miller
18. Eddie Lacy
19. Reggie Bush
20. Frank Gore

Wide Receivers

1. Calvin Johnson
2. Dez Bryant
3. A.J. Green
4. Demaryius Thomas
5. Julio Jones
6. Andre Johnson
7. Brandon Marshall
8. Hakeem Nicks
9. Jordy Nelson
10. Larry Fitzgerald
11. Pierre Garcon
12. DeSean Jackson
13. Roddy White
14. Dwayne Bowe
15. Torrey Smith
16. Victor Cruz
17. Vincent Jackson
18. Marques Colston
19. Kenny Britt
20. Randall Cobb

Tight Ends

1. Rob Gronkowski
2. Jimmy Graham
3. Vernon Davis
4. Heath Miller
5. Tony Gonzalez
6. Jason Witten
7. Antonio Gates
8. Greg Olsen
9. Jared Cook
10. Coby Fleener
11. Kyle Rudolph
12. Zach Miller
13. Owen Daniels
14. Jermichael Finley
15. Fred Davis
16. Brandon Myers
17. Jermaine Gresham
18. Dustin Keller
19. Rob Housler
20. Brandon Pettigrew