A player who finishes the preseason still on the PUP list can then be moved to the reserve/PUP list. Such players must sit out the first six weeks of the regular season. At that point, teams have a five-week window in which to allow the player to begin practicing; from the day the player begins practicing, teams have an additional 21-day window in which to decide whether to activate the player to the 53-man roster. If either of those deadlines pass, the player must remain on the PUP list for the remainder of the season.<ref>{{cite news |title=NFL Makes Minor Change to Physically Unable to Perform (PUP) List Rules |url=http://www.sportsmedia101.com/newyorkgiants/2013/07/27/nfl-makes-minor-change-to-physically-unable-to-perform-pup-list-rules/ |work=sportsmedia101.com/ |date=July 27, 2013 |accessdate=2013-10-18}}</ref>
Similar lists, known as the "non-football injury" or "non-football illness" (NFI) lists, are functionally equivalent to PUP, but are used for players who are unable to practice as a result of conditions unrelated to football, or injuries that did not occur during an NFL game or practice. However, all players placed on PUP are eligible to return to the active roster during the season, but only up to two players from the NFI lists are eligible to return to the active roster.
[[Willis McGahee]] spent his entire rookie season on the [[Buffalo Bills]]' non-football injury list due to the major knee injury he sustained in the [[2003 Fiesta Bowl]] while in college.<ref>{{cite news |title=McGahee put on non-football injury list |url=https://www.espn.com/nfl/news/story?id=1603633 |website=ESPN.com |date=August 26, 2003 |accessdate=September 26, 2019}}</ref> [[New England Patriots]] tackle [[Marcus Cannon]] began his rookie season on the non-football illness list as he recovered from [[chemotherapy]] for [[non-Hodgkin lymphoma]] in 2011.<ref>{{cite news |author=Florio, Mike |title=Marcus Cannon added to Patriots’ active roster |url=https://profootballtalk.nbcsports.com/2011/11/15/marcus-cannon-added-to-patriots-active-roster/ |website=NBCSports.com |date=November 15, 2011 |accessdate=September 26, 2019}}</ref>
