The NFL and the NFL Players Association have negotiated changes to the league's COVID-19 protocols, some of which are being put in place immediately and could help teams whose rosters have been decimated this week.
Effective immediately, all 32 NFL teams will be placed in intensive COVID-19 protocols until the conclusion of Week 15. This means the reimposition of mandatory mask wearing in team facilities, social distancing, grab-and-go meal service in team cafeterias, all-virtual meetings, limits on the number of people allowed in weight rooms and restrictions on activities outside the facility.
Teams already in intensive protocols due to ongoing outbreaks will continue daily testing of all players and personnel -- vaccinated or not -- but the rest of the teams won't be subject to daily testing.
Also effective immediately, the league and the NFLPA will institute changes in the return-to-play COVID-19 protocols that will make it easier for players who are vaccinated and asymptomatic to return to practice and games.
Under the previous protocols, a vaccinated individual who tests positive for COVID-19 has to produce two negative tests 24 hours apart before being cleared to return. The new protocols relax that requirement and could enable teams such as the Cleveland Browns, Los Angeles Rams and Washington Football Team to get some players back for this weekend's games.
In creating the new return-to-play protocols, the NFL and NFLPA focused on a new metric that measures the viral load of a player, known as the "cycle threshold" (CT). In essence, the CT value can measure whether a player is still contagious, even if in some cases he would still test positive on a traditional test.
That testing can begin as soon as one day after the initial positive and could significantly shorten the amount of time a vaccinated player spends away from the team facility.
There are now three ways for a vaccinated player to return under the new protocols:
• Two PCR (polymerase chain reaction) tests that are either negative or produce a CT value of 35 or greater.
• One PCR test that is either negative or produces a CT value of 35 or greater, and a negative Mesa test result taken with 24 hours of the PCR test. (Mesa tests usually return results in less than an hour.)
• Two negative Mesa tests.
According to NFL chief medical officer Dr. Allen Sills, previous NFL test analysis has shown that players with CT values at the level of 35 or higher do not transmit COVID-19 and thus would not be contagious.
"It's not about loosening our standards," Sills said. "If anything, we're just bringing a higher degree of precision in measuring ourselves against a more precise ruler."
There is no change to the rules for unvaccinated players, who will continue to be tested daily and must stay away from the team facility for at least 10 days before they can be cleared to return after a positive test.
"Throughout the pandemic we have continuously evolved our protocols to meet our goal of advancing the safety of the players, coaches and staff," the league said Thursday in a statement. "The changes we are making today aim to address the increase in cases and the advent of the Omicron variant. Effective immediately, all clubs will implement preventative measures that have proven effective: masking regardless of vaccination status, remote or outdoor meetings, eliminating in-person meals, and no outside visitors while on team travel. We will continue to strongly encourage booster shots as the most effective protection.
"Finally, and based on expert advice, we will adjust the return-to-participation requirements for those who have recovered from COVID-19. All of these changes are grounded in our data and science-backed approach, with safety our number-one goal for the entire NFL community."
The NFLPA also is pushing to allow players the ability to opt out of the season if they are uncomfortable with changes to the protocols, though it's unclear whether the league would agree to that.
As of Thursday afternoon, there was no plan to mandate COVID-19 booster shots for vaccinated players, though the league and the NFLPA continue to strongly encourage unvaccinated players to get vaccinated and vaccinated players to receive boosters.
The Cleveland Browns, meanwhile, announced Wednesday that head coach Kevin Stefanski has tested positive for the coronavirus, and at least eight starters -- including quarterback Baker Mayfield -- have been placed on the reserve/COVID-19 list this week.
The Los Angeles Rams have placed 13 players on the reserve/COVID-19 list in the past week, including star cornerback Jalen Ramsey, star receiver Odell Beckham Jr. and starting running back Darrell Henderson.
Washington has placed 17 players on the reserve/COVID-19 list this week -- including eight on Wednesday and three more on Thursday -- bringing its total to 21 overall and 11 starters.
ESPN's Kevin Seifert contributed to this report.