With 53-man rosters set, every NFL team hopes to have built up enough depth to get through the 2017 season and its impending run of injuries. Last season, New England won the Super Bowl after losing All-Pro tight end Rob Gronkowski, because Martellus Bennett was a high-quality replacement. And after already losing Julian Edelman this season, the Patriots have built up enough depth at wide receiver, with Brandin Cooks, Chris Hogan, Danny Amendola, Malcolm Mitchell and now the recently added Phillip Dorsett, that the loss of Edelman won't be felt as much as it would on a team with lesser depth.
Moreover, if a team is already weak at a position, then an injury there is unlikely to make things much worse. For example, Pittsburgh has a weakness at tight end, so an injury to Jesse James or newcomer Vance McDonald wouldn't really change much for the Steelers.
However, some injuries are much harder to overcome. When Oakland lost Derek Carr to a broken leg in Week 16, the Raiders' playoff hopes were dashed; the drop from Carr to rookie backup Connor Cook was too steep. The fact is just about every contender would be in serious trouble if the starting quarterback were lost for the season.
We wanted to focus instead on the worst depth situations for the other offensive and defensive units, looking at teams for which an injury to a starter would cause the biggest problems. Any references to pass-pressure stats are courtesy of Football Outsiders' game charting project in coordination with Sports Info Solutions.