We've already seen a few big-name players such as Jeremy Maclin and Dennis Pitta get struck down early in training camp with season-ending injuries. Most NFL teams have the depth to overcome similar losses, even to quality starters. So while the Philadelphia Eagles and Baltimore Ravens will have to make some adjustments to their respective offenses, they shouldn't be dealt too much of a setback.
There are, however, some players who are truly impossible to replace. Which offensive superstars are backed up by a mixture of the weak and the unproven?
For each of the offensive skill positions, we went through and looked at the five most irreplaceable players in the NFL -- based not just on the quality of the player, but the quality of his backups. Yes, most backups will change the game plan of their teams -- especially at quarterback -- but it does matter if a team has a competent backup like Shaun Hill as opposed to your local neighborhood McCown brother or undrafted rookie free agent.
Quarterbacks
1. Aaron Rodgers, Green Bay Packers
Graham Harrell (an undrafted free agent) and B.J. Coleman (seventh-round pick) are the backups. They have a combined four regular-season pass attempts and both have been iffy in the preseason. Ted Thompson deserves the benefit of the doubt when it comes to young players, and maybe the Packers would be finished even if they had a reliable backup quarterback. But if Rodgers does go down, this team is sunk. It's hard enough to imagine Green Bay competently executing its passing attack with a backup quarterback, but throw in the quality of their offensive line and Rodgers' ability to buy time in the pocket, and the situation could get ugly.