If the Detroit Lions decide to keep five interior offensive linemen this year, they will have five different options for one spot.
When the Detroit Lions kicked off the 2014 regular season, they only had four total interior offensive linemen on their roster: a starting left guard, a starting center, a starting right guard and one backup. That left the Lions pretty thin at guard and center, but it allowed them to keep an extra player at another position.
This year, the Lions could very well go the same route in order to create room at another position, but my feeling is that there will in fact be a second backup spot for the guard and center positions.