Details are starting to trickle out on the new injured reserve rules adopted by the NFL and NFLPA. The new rules which will allow a player to go onto IR and return that season will include an exemption for this year only for those players who have already been placed on IR.
The highlights of the new rule are that a "major injury" is defined as a player that's out for six weeks, a player has to be "designated for return" at the time of his placement on IR and a player can return once he's been on the IR list for eight weeks.
The release on the new rules describe how this will work.
1. Only players with a "major injury" who are placed on Reserve/Injured after 4:00 p.m., New York time, on Tuesday, September 4, or thereafter during the season, will be eligible to be reactivated at a later time.
2. A "major injury" is defined as an injury that renders the player unable to practice or play football for at least six weeks (42 calendar days) from the date of injury.
3. Each team may reactivate only one player placed on Reserve/Injured after 4:00 p.m., New York time, on Tuesday, September 4. That player must be "designated for return" at the time the club places him on Reserve/Injured, and such designation shall appear on that day's Personnel Notice.
4. Such player is eligible to return to practice if he has been on Reserve/Injured for at least six weeks from the date he is placed on Reserve. He is eligible to return to the Active List if he has been on Reserve/Injured for at least eight weeks from the date he is placed on Reserve.
The part about designating a player for a return at the time he is placed on IR should be emphasized; you can't just wait and see on a player.