Jonathan Taylor, the disgruntled Indianapolis Colts running back, wants out of the team. But according to veteran Colts insider Mike Chappell, the front office has found a way to prevent him from leaving: the Non-Football Injury (NFI) list.Conveniently, Taylor had hurt his back during an individual workout in Arizona. He is also still recovering from his ankle injury and is currently listed as Physically Unable to Perform (PUP). On Sunday evening, Mike Chappell reported that the Colts were condisering to place Jonathan Taylor on the non-football injury (NFI) list:Mike Chappell@mchappell51Breaking: Colts considering placing Jonathan Taylor on non-football injury list (NFI), per source. He suffered some type of back injury while working out on own in Arizona. Also still rehabbing from January ankle surgery. Currently on PUP.710230Breaking: Colts considering placing Jonathan Taylor on non-football injury list (NFI), per source. He suffered some type of back injury while working out on own in Arizona. Also still rehabbing from January ankle surgery. Currently on PUP.The development is major news because it allows the Colts to withhold his entire 2023 salary, meaning they can forcibly extend his tenure to the end of 2024 without him even playing a down. Taylor, through his agent Malki Kawa, has been wanting an extension, like most running backs.But what is the NFI list exactly?Physically Unable to Perform (PUP) denotes injuries suffered during football-related activities before camp has begun. Meanwhile, Non-Football Injury (NFl) obviously denotes injuries suffered outside of football, like home incidents; however, it can also apply to rookies who are carrying a lingering injury from their collegiate days.Both types of players must be medically cleared before they can return to the roster, but once it happens, they cannot be returned there. Once the regular season begins, a couple differences arise:PUP players must sit out four weeks; NFI players six weeks.PUP players have a five-week window during which teams must decide whether to allow them to practice. NFI players, meanwhile, can resume practice immediately but cannot be activated until after their team's eighth game.Once these players resume practice, teams have an additional three weeks to decide whether to promote them to the active roster. Once the weeks pass without a decision, these players must sit out the season.Other NFL players on the NFI list in 2023Jonathan Taylor is not the only player on an NFI list in 2023, but as a former All-Pro and Pro Bowler, he is the most prominent.Green Bay defenders Tariq Carpenter and Tarvarius Moore were placed on the NFI list almost a week ago. They join rookies Grant DuBose and Camren McDonald.Staying in the NFC North, Chicago Bears wide receiver Dante Pettis has also made the NFI list. So has Las Vegas Raiders DT Neil Farrell Jr. while another DT, New England Patriot DaMarcus Mitchell, has been cleared off it. Ravens offensive lineman Andrew Vorhees has also been a part of the NFL list.