As rookies report to training camps with veterans not far behind, general managers and personnel chiefs across the NFL are still looking for guidance on just how many players can be on their rosters this season.

The 90-man rosters we've come accustomed to may shrink to 80 to start training camp. Or 90 will be allowed to begin camp with teams working their way to 80 after a certain amount of time. At this point, no one is sure.

Health and safety are paramount as the NFL endeavors to play a sport totally incompatible with physical distancing. And with the erasure of all preseason games, it is clear team owners and players are aligned in making sure unnecessary risk is eliminated in the pursuit of beginning a 17-week regular season.

But there are basic roster questions that GMs across the league still don't have answers to. Several sources I've spoken with this week remain flummoxed on whether they'll have to cut undrafted free agents who they gave big (guaranteed) signing bonuses to back in April. If a player tests positive for COVID-19 upon return to the facility in the coming days, will he count on the roster or receive an exemption? Will GMs be forced to cut players before they can get them in the building for a physical, much less before a conditioning test and weeks before they ever get on the field?

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There are pertinent questions with less immediacy, too. How big will practice squads be? Will there be certain "protected" players? Will players be able to accrue a season toward their pension while languishing on the practice squad? Though important and necessary to the start of the regular season, these questions don't have to be worked out before players report to camp.

It's not exactly the hardest part of the job for GMs to figure out how to cull a roster from 90 to 80. Most years a good team beat reporter can figure out 45 to 48 of the team's eventual 53-man roster before camp even starts. But the 10 or so players in peril here figure into teams' long-term plans far more than any starting job in Week 1.

It's entirely conceivable that a UDFA with a fat signing bonus won't take the field for his team whenever practices begin in August. Might a GM cut a late-round draft pick because of a need at another position group?

All of this depends on the construction of the roster. One GM noted to me that he'll look more at the position groups that are older or more prone to injury. If most of your starting linebackers are grizzled vets that you anticipate giving vet days to, maybe you keep down-the-roster linebackers to fill in for those off days.

Another GM noted it's harder to find quality guys in the trenches, so one team may be more inclined to keep offensive and defensive linemen as opposed to a ninth or 10th receiver that may be considered a dime a dozen.

The math for preseason roster building is different this year. Usually teams have what's essentially a formula for how many players at certain position groups they need. But that is based on the number of bodies you need to make it through four quarters of "meaningless" preseason football. A coach may not want to play his starting cornerbacks in most or all of the exhibitions, so he keeps another two on the 90-man roster for the games. With no preseason football this year, that won't be necessary.

Unfortunately, injuries are part of the game. No matter what this acclimation period over the next month looks like, players will get injured during strength and conditioning or non-padded practices. Any other year, if an injury occurred during a morning practice, a GM would have three to five players on a flight to camp that evening and working out the next day before signing one.

Again, not this year.

As it stands today, a team could sign a player sight-unseen and still not have him inside the team facilities for four to five days. That's because the entry-to-camp rules collectively bargained by the league and union state that a player must test negative, wait two days and test negative again before joining the team. In the best-case scenario, a player would have to be in town for at least two days before he is proven negative for COVID-19 and passes a physical.

Of course, those rules may change once camps are underway. But whether it's Jadeveon Clowney finding a new team or the third-string left guard looking for a home, the wait will be on.

That's why some inside league circles are advocating for a sort of small, team-specific bubble. Call it a ready squad. Each team would have a dozen or so players who are technically on the team but not counting toward the roster (perhaps the 10 players you otherwise would have cut to get to 80). They remain quarantined and/or tested regularly while also being a part of virtual meetings with strength and position coaches. If an injury happens, they are in position to get the call and join the team in seamless fashion.

That'd be music to any GM's ears. But it's not a position the union is likely to take. What you're essentially asking these players is to sit in a hotel or wait around for a call that may never come. Meanwhile, if that player were a free agent, he would be free to sign with any team that calls and begin working toward his dream within the next five days.  

That's a hard ask for guys who aren't even officially on teams, but something enough players may be willing to do if that's what it takes for their shot at the NFL.

Neither the league nor the union is to blame for this unique set of challenges, but both sides have to work together quickly to get the answers. Everyone is trying to eliminate unnecessary risk as much as possible to safely return to play. Smaller roster sizes accomplish that, but the issues that arise from that have to be handled as well.