Patriots linebacker Dont’a Hightower is one of eight New England players and about four dozen NFL players to opt out of the 2020 season because of coronavirus concerns. Elise Amendola/Associated Press

NFL players who decide to opt out of the coming season must do so by Thursday afternoon, a person familiar with the agreement between the league and the players told The Associated Press.

There also are opt-out provisions for players who experience emergency or extenuating circumstances during the season due to the coronavirus, the person said, speaking to the AP on condition of anonymity Tuesday because the changes to the collective bargaining agreement have not been made public.

Those provisions would cover a player with a severe family situation related to COVID-19 or if he is diagnosed with a high-risk condition after Thursday’s deadline.

Any player who opts out and is in the high-risk category will receive a $350,000 stipend for 2020, with his contract paused. Players in the voluntary opt-out category will get $150,000 in the form of an advance on a contract.

Another person with direct knowledge of the agreement between the league and the players’ union said that relief in the 2020 salary cap is being provided to the 32 teams. If a player opts out, his contract is paused for a season. Any signing bonus that was being applied to the salary cap in 2020 now will be delayed a year.

So, if a player signed a four-year contract with a $16 million signing bonus, the bonus normally would be applied against the cap at $4 million per season for four years. But the $4 million for 2020 will not be applied for another year, even though the player has collected his full bonus.

Already, some four dozen players have opted out of playing due to the pandemic, including eight members of the Patriots. By not applying any signing bonuses to 2020, several million dollars could be freed up for signing new players. That gives teams more flexibility should players contract the coronavirus and be unavailable.

LIONS: Detroit removed quarterback Matthew Stafford from the COVID-IR list and said he received a false positive test result.

The list was created for players who either test positive for COVID-19 or have been in close contact with an infected person. Stafford was listed on it Saturday, but the team said Tuesday his testing sequence for the pre-entry period was: negative, negative, false positive – then the next three tests were all negative.

“To be clear, Matthew does NOT have COVID-19 and never has had COVID-19 and the test in question was a False-Positive,” the team said in a statement. “Also, all of Matthew’s family have been tested and everyone is negative.”

VIKINGS-RAIDERS TRADE: The trade that sent defensive tackle P.J. Hall from Las Vegas to Minnesota for a conditional draft pick has been negated after Hall failed a physical with the Vikings.

Minnesota agreed Monday to send a conditional seventh-round pick in 2021 to the Raiders for Hall. The Vikings sent him back to the Raiders on Tuesday and he was waived by Las Vegas.

Hall was a second-round pick in Coach Jon Gruden’s first draft back with the Raiders in 2018, selected 57th overall out of Sam Houston State.

GIANTS: New York improved its pass rush by re-signing linebacker Markus Golden.

Golden’s contract is a one-year tender for $5.1 million.

Golden was a free agent in the offseason who went unsigned. The Giants placed a unrestricted free agent tender on him after the draft and when he did not sign with another team by the first day of training camp, New York regained exclusive rights to his services for this season.

Golden had 10 sacks in 2019, more than twice the total of any other Giants defender. The 29-year-old is entering his sixth season.

BUCCANEERS: Six-time Pro Bowl running back LeSean McCoy has finalized a one-year contract with Tampa Bay.

The 32-year-old McCoy agreed to terms last week and is entering his 12th season. He has started 141 of 160 career games, rushing for 11,071 yards and 73 touchdowns while also impacting the passing attack with 503 receptions for 3,797 yards and 16 TDs with Philadelphia, Buffalo and Kansas City.

DOLPHINS: cornerback Cordrea Tankersley was activated off the reserve-COVID-19 list and then waived Tuesday.