Here's Tony Villliotti latest article on the myriad of changes to roster for each NFL team. See http://www.draftmetrics.com/files/RETAINING%20STARTERS%20AND%20FREE%20AGENTtrainingcamp.pdf
Highly interesting and it coincides a bit w/my own little spreadsheet/database. I prefer to use http://www.pro-football-reference.com/ and I create a page for each team every season.
What's missing.. ST of course, though the saying is ST counts as one third of the team, they aren't on the field one third of the time. ST are counted on between drives or at the end or start of a drive. It's difficult to have an exact measurement of their portion of the game. I looked at the one third portion and thought it was way too much, thought about one fourth (and five eights for O & D) and still decided that was way too much. I finally settled on a portion of 2/12 (and 5/12 for O & D).
The other missing issue is accounting for injury (difficult to assess again due to will the player progress, regress or stay the same) and I think in the future game suspension will need to be address'd. I believe for the majority of players that the NFL teams bring them back onto the field to soon and thus they re-injure themselves or aren't playing up to the required standard and are either cut or replaced by another player.
The mindset of NFL teams should be that with so much money tied up in this investment, I need to give it time to heal and perform again at expected levels. I think some players won't truly be healed until a year or a year and a half has passed. The NFL teams seem to be in a hurry to get their players back on the field and have yet to produce players back from injury at a truly productive level IMO.
Perhaps the NFL teams should have a separate medical salary cap instead of including all players under the present 120M cap umbrella.
Let's say that teams will still have their 120M cap for healthy active players. Those players designated as not healthy or inactive for whatever reason will be placed on a separate cap of 40M. This would allow teams to bring in additional players to replace injured players as injured players would be added to the medical cap and their worth subtract from the active cap.
This would also allow teams to let players to progress to their level of athletic talent, which is the greatest benefit for the players IMO. It's like having enough rest before you go to work. Sure their may be a few people who can work with just four hours of rest each night, but the majority of people need their eight to ten hours. Anyone consistently having less rest will make more mistakes each day, at work, on the commute and elsewhere. The greater the complexity of your work whether it's physical or mental the greater amount of rest required IMO.
I also think even if doctors believe the physical injury has healed that the players psyche has just as much importance in the healing process. The players level of confidence has to be high if they are to perform at their original superior athletic levels and if not they will need to learn what to do to compensate for this new found lack of athletic level if they are to step onto the field again (for example, keep more distance between yourself and your opponent).