Now that the NFL world is days, if not hours, away from kicking off training camp, there's been an abundance of acronyms like PUP (Physically Unable to Perform) floating around. Players are taking physicals and if they fail those physicals, their respective teams have options. For example if a player suffered a football-related injury during the offseason (cornerback Dre Kirkpatrick), or continues rehabilitating an injury from last year (wide receiver Jordan Shipley), they can be placed on PUP.
Wait. PUP. No. That hurts the beginning of the regular season. Settle down, skittles. Despite everything that's being said or written, there are two forms of the PUP list. There's the Active/Physically Unable to Perform and the Reserve/Physically Unable to Perform. The difference is rather significant, which may have a meditative-like calming affect.
Active/PUP relates to players being unable to start training camp with a football-related injury. There is no rule governing them to sit out of practice for any amount of time. Once they are medically cleared, they're allowed to practice that moment. For example if Shipley goes on Active/PUP to begin training camp, he's eligible to practice once Cincinnati's medical staff clears him. At this point, every mention of PUP that you're seeing pop up around the NFL, refers to the Active/PUP. It's the less catastrophic Armageddon version, but it enables players to eventually become eligible for the other PUP list (which benefits teams with players still recovering).
Then there's the Reserve/Physically Unable to Perform List. If by the end of the preseason a player isn't medically cleared yet, he can be transferred to the Reserve/PUP, which prevents that player from playing and practicing during the first six weeks of the season -- however that player doesn't count against the 53-man roster. If the player isn't activated after the sixth week, the team has a three-week window to make a decision (injured reserve, release, activation).
So if Kirkpatrick or Shipley are placed on PUP on Thursday (or Friday), it's the active list. Meaning that once they're cleared, they're ready to practice and the start of the regular season has no impact. However if they remain on Active/PUP following the final preseason game, then they're candidates for the Reserve/PUP, which impacts their playing time for the first six weeks, but frees their spot on the roster for another player.
However once a player practices during training camp, all options of the Physically Unable to Perform list are off the table. For example, Antonio Bryant came into training camp in 2010 with a serious issue in his knee. If the team placed him on Active/PUP, he could have been eligible for the Reserve/PUP list and allowed to rehabilitate for several months before the team needed to make a decision. Instead he practiced during the first training camp session and was thus ineligible for Reserve/PUP -- therefore they ended up eating Bryant's signing bonus and other guarantees he earned in his contract, cutting him before the regular season without the option of observing any improvement and using him if he recovered.