There was some mention in one of the main threads suggesting that the NFL could benefit from IR Rules similar to Baseball.
It used to be that roster sizes were 45 men and clubs were allowed to place players on IR and bring them back later in the year.
But, from what I understand, it was used to "park" players on IR as kind of an undefined holding area -- kinda like purgatory.
Then, the 53 man roster came about with 45 active on game day. That way, if you had a player who would be out of action for 4 or 5 weeks, he remains on the roster and is declared inactive for game day. The active roster was recently increased to 46 to alleviate the special rules surrounding the third string quarterback.
The problem with the 53 man roster, is that each roster spot has proven so valuable, that teams will IR a player for the year, yet he may have a legitimate chance to be healthy by the end of the year.
Think Victor Cruz in 2010. He was a bubble player that year. Had a hammy or something within the first three games or so. Rather than wait out the 4 to 6 weeks that it probably would have taken to heal, the Giants put him on IR and got another player to put on the 53 man roster.
Given the need for bodies just to hold decent practices, there should be several tiers of NFL roster membership.
* 53 Man Roster (as currently run)
* Short Term IR (as needed for "short term injuries -- min 4 weeks)
* Developmental Squad (4 to 6 guys not on 53 man roster, but club has exclusive rights to these guys for one year. Base pay scale is halfway between equivalent Roster spot and Practice Squad spot. Club can "Activate" or "Deactivate" player up to 4 times each year without going through waiver process to replace players on Short Term IR. Pay varies based on whether player is "active" for week or not.
* Practice Squad (4 to 6 players under current Practice Squad format) No protection from other teams signing members of Practice Squad.