The 2012 offseason has not yielded a lot of change in the Detroit Lions starting lineup.
In fact, the Lions have made many moves to prevent changes among the starters. They have also been focusing on improving the quality of their depth players. As a result, the Lions have acquired not only good starters, but invaluable backups.
Which of those players is most valuable to the Lions' success?
The Lions have backups who are of starting-quality, and they have backups who are just solid backups—but at exceptionally important or oft-injured positions.
All of those players are important to the Lions this season. There's no such thing as an NFL season without injuries, so backups are going to come in from somewhere at some point this season.
These are the guys who offer the Lions the best insurance policy if that happens.