The 49ers have drafted several players with pre-NFL injuries, had a good share of players sustain injuries last season, and even suffered the loss of wide receiver Michael Crabtree in organized team activities. Injuries are an inherent part of football.

The NFL and NFL Players Association have agreed on terms to allow injured athletes to return. However, when a player suffers an injury, the team is given a variety options. In several articles, there have been inquiries in the comments section asking about our injured players and what options are available. It appears Niners Nation likes specifics and delves deeper into the details. So, we look at the difference between the PUP (Physically Unable to Perform), the Non-Football Injury (NFI) and IR (Injured Reserve) lists, and what that means for our injured players.

Physically Unable to Perform (PUP) Rules

First, under the NFL Rules, there are two classifications of Physically Unable to Perform (PUP). There's the Active/PUP and the Reserve/PUP. Both PUP classifications are for football-related injuries.

The Active/PUP (Preseason PUP list) allows players who are unable to start training camp the ability to sit out until the medical staff provides clearance. Once they are medically cleared, they're allowed to practice immediately.

For example, Kyle Williams suffered a football-related injury to his ACL in New Orleans. He, as one example, will likely begin the training camp on the Active PUP. Once he receives full clearance from the 49ers medical staff, he is eligible to practice. Although he showed a "green light" icon on his Twitter and Instagram accounts, he has only been performing individual drills. He is yet to actually practice with the team.

Another player who is likely to start on this list is Kendall Hunter. He suffered a season-ending Achilles injury on the same play that injured Williams, and performed individual drills in front of the 49ers medical staff. He too, is awaiting clearance to practice with the team.

Second, there's the Reserve/PUP (regular season PUP list). Any player starting on the Active PUP list (and has not practiced) with the team becomes eligible for the Reserve/PUP. Once a player practices during training camp, all PUP list options are off the table. This is important to note. Both Williams and Hunter could be cleared within a day or two of the start of training camp, but starting them on the PUP list leaves it on the table as an option if there is a setback.

If, during the season, a player sustains injury but practiced at camp, the PUP list is not an option. The team can keep the player on the roster, if they believe he will come back that season. But, the injured player is counted against the 53-man roster.

In the alternative, teams must go straight to the Injured Reserve list (lose the player for the remainder of the season) or waive the player. So, it means the 49ers are extremely cautious about letting any player practice, no matter how good he looks following an injury. As you can see, letting a player practice makes the difference. Allowing a player to "practice" limits options. It can tie up roster spots and, more importantly, dollars.

It should be noted, ALL player salaries of a team count in calculating that team's total salary cap during the season. This includes players that are on Injured Reserve (IR), Physically Unable to Perform (PUP), and the Practice Squad (PS).

If a player started on the Active/PUP list and isn't medically cleared by the end of the preseason, the 49ers may transfer any Active/PUP player to the Reserve/PUP.

These players are prevented from playing and practicing during the first six weeks of the season. What makes the Reserve PUP advantageous is that any player on the Reserve PUP list does not count against the 53-man roster. If a player isn't activated after the sixth week, the team has a three-week window to make a decision to: 1.) place the player on injured reserve; 2.) release the player; or 3.) get him back to practice. As soon as the player returns to practice, the team has another three-week window to add the player back to the 53-man roster, or place them on the Injured Reserve list.

For example, Mario Manningham is a good candidate to see the Reserve/PUP this year. It buys the team some time to allow the players to resolve their injuries and protects both the players and the team from waivers.

It is entirely possible the 49ers could use the Reserve/PUP with Michael Crabtree. If Crabtree recovers within the 6-month time frame projected, he could go nine weeks into the season before he must be practicing again. The team would then have another three weeks (Week 12) to return him to the 53-man roster. After that point, they can have him as one of the inactive players on game day, but he would still have to be on the 53-man roster.

If Crabtree is progressing well, the 49ers could activate him making him eligible to play. Even though Crabtree would occupy a spot on the 53-man roster, the 49ers may see this as the best option available. If he is medically able to return for the playoffs, for example, they may be willing to go a man short for a few weeks -- just to keep that door open.

Non-Football Injury (NFI) List

The NFL has a second injury list that is similar to the PUP list, but is based on different timing of injuries. The Non-Football Injury list has rules that closely adhere to those in the Active/PUP and Reserve/PUP, but it is classified differently. The most obvious inclusion would be injuries suffered off the football field (game AND practice fields). If a player gets hurt away from team activities, the team would be eligible to place him on the NFI list.

Additionally, a draft pick who sustained any injuries before being selected by his NFL team can be placed on this list. This covers ANY injury suffered before the draft, including injuries on the football field at the collegiate level. Players like Luke Marquardt and Marcus Lattimore, for example, would start on the NFI list. You may recall that running back Jewel Hampton was on the NFI list due to a pre-NFL injury. Hampton as activated after Week 12, days after Kendall Hunter tore his Achilles.

Injured Reserve (IR) List

If the team decides to place a player on injured reserve, it must be a major injury. The NFL defines major injury as an injury that renders the player unable to practice or play football for at least six weeks -- or 42 calendar days -- from the date of injury.

The NFL and the NFL Players Association agreed to a new short-term IR rule change which took effect last year. This change allows one player (per team) to be activated from the IR list. Before the enactment of this rule, any player that was placed on the IR list was not eligible to play again for the same team in that season (regular season and postseason).

So, while the NFL does not limit the number of players on the PUP or IR, the salary cap sets its own constraints. One of the reasons the salary cap came into effect is the alleged abuse of the IR list to get around the NFL roster limit. High revenue teams, like the Dallas Cowboys, allegedly had the ability to redshirt unlimited young players by claiming they were injured (when they weren't). Teams could place unlimited players on IR, thereby circumventing the roster limit.

The salary cap effectively curbed the abuse of limitless players on IR. However, another problem was created. As stated previously, those on IR receive full pay for the season (and it's counted against the cap), but are forbidden to dress again for the entire season. If a team believed the player could return that season, they had to keep the player on the 53-man roster (thereby occupying a precious roster spot). In this scenario, it is anything but a "level playing field" the NFL claims to be providing with these rules. This kind of occurrence is likely why the NFL and NFL Players Association came up with the player designation rule.

The one player selected must be immediately "designated for return" at the time he is placed on the list. That designation must appear on the day's Personnel Notice. That designated player is eligible to return to practice if he has been on the IR list for at least six weeks from the date he was placed on Reserve. He is eligible to return to the active list if he has been on the IR list for at least eight weeks from the date he is placed on Injured Reserve.

If the 49ers do use the Reserve/PUP with Michael Crabtree, the medical designation may available if needed. The point is the 49ers have some flexibility with injured players. If needed, the 49ers would undoubtedly be willing to use their one designation on Crabtree. Based on last season's performance, the 49ers could easily make use of the new rule.

It could buy Crabtree and the 49ers more time. If healthy, he actually has a good shot at returning this season. Depending on each circumstance and rehabilitation during the season, we may see several injured athletes begin on one of the PUP lists, and if necessary, be transferred to the IR list. Perhaps, for a time, he may progress through every list. Of course, only time will tell. One thing is certain: We all wish our players a speedy recovery.

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