If the NFL is able to conduct a 2020 season, players will participate under a number of coronavirus-related restrictions on the field and off. That could mean playing in specially designed face masks and potential fines for off-field activities that lead to the spread of the virus.

The National Football League Players Association conducted a two-hour conference call Thursday with team player reps and NFLPA medical director Thom Mayer, and the call centered on the protocols the league and the union have been discussing to allow players to participate in training camp and the regular season amid the coronavirus pandemic. Players were told that the chances of conducting a season around the virus will depend on the success of their testing and contact-tracing program and were given details about what they could expect and what would be expected of them.

One source told ESPN that players on the call were told that they could be fined for conduct detrimental if they are found to have engaged in "reckless" behavior away from the team facility, such as eating out in restaurants and using ride-sharing services. They also were updated on the progress league and union medical personnel are making on protective face shields that could be worn while playing, practicing, working out and moving around team facilities, though sources who were on the call said the players are pushing back against those face shields for various reasons, including concerns about how it might affect their vision and their breathing.

The call began, sources told ESPN, with updates from Mayer on the virus in general. The player reps were told, among other things, that testing can decrease transmission but that the virus is very serious and should be taken seriously, that African American males are more susceptible to it, that it is possible to get it a second time even if you've already had it and that false negative test results are enough of an issue that players who test positive would be required to test negative twice before they are allowed to return.

Players were told that there has been discussion about wearable contact tracers that would allow teams to identify people with whom an infected player had interacted, and that if they tested positive their families could be tested as well.

There is a larger call scheduled for Friday that's open to all players, not just reps. Sources told ESPN there was plenty of pushback on Thursday's call from players asking why they are trying to rush back to play if the virus is such a dangerous threat. Players also have been asking what happens to their contracts if they opt not to play for virus-related reasons (as some NBA players already have), what happens if they grow too uncomfortable to play as the season goes on and what happens to next year's salary cap as a result of lost revenue this year.

But the union officials on the call said those issues have yet to be worked out. "There are questions guys want to get answered before we play," one source said.

Other details addressed on Thursday's call:

• Some team meetings could potentially be held in person, but only smaller ones. Most meetings will be conducted virtually.

• Teams will limit access to the facility to "essential" employees only, and facilities will be cleaned and disinfected around the clock.

• Teams will be required to submit emergency-response plans regarding the coronavirus, including procedures that would follow a positive test from someone in the building.

• Media access is expected to be limited. Media would be required to go through the same testing protocol as players and other personnel, and media interviews are likely to be conducted virtually rather than in person.

• Currently, the proposal is to test players and team personnel every other day during training camp, but player reps on Thursday's call said they would prefer daily testing. Availability of and access to testing is an important issue, and the league is conscious of the potential backlash it could face if it has greater access to testing than the general public.

• Players and coaches usually stay in hotels during training camp, but players are being told they will stay in their own homes and commute to team facilities this year.