Active/PUP is a preseason designation for players who have sustained or are recuperating from offseason ailments. They can practice and play as soon as their respective team's medical department clears them. The Reserve/PUP position is utilized throughout the regular season. A player in this status may be activated at any time by his team. The designation was created by the NFL in 1998 to help balance the number of starters on teams. That year, all 32 teams had an "average" number of players on injured reserve (IR). To compensate for some of these injuries, each team was given four additional spots on their active roster for a total of 75. These additional players could come from any other spot on the roster, including the practice squad. Teams could use these extra slots either to fill out their own injured reserves or to replace players lost through free agency or retirement. In addition to those four openings, there were three other positions that needed to be filled by another player: the starting quarterback, two starting wide receivers, and a starting tight end. Each team was required to have a minimum of 13 players on its active roster during the regular season. If a team had more than 13 players on its active roster, it would have to cut one of its inactive players. Teams can place players on injured reserve during the season, after they've played in at least four games.