Cleveland Browns center JC Tretter, the NFL Players Association president who has been pushing for daily COVID-19 testing all season, said he tested positive for the virus on Thursday. Seth Wenig/Associated Press

New Orleans Saints quarterbacks Taysom Hill and Trevor Siemian, Minnesota star running back Dalvin Cook and Cleveland center JC Tretter, the NFL Players Association president, tested positive for COVID-19 on Thursday.

But Washington is getting back quarterback Taylor Heinicke.

Hill and Siemian were among nine players for New Orleans placed on the reserve/COVID-19 list. Safety Malcolm Jenkins is also on the list, but the Saints expect tackle Jordan Mills to return for Monday night’s game against Miami.

The situation left Ian Book, a rookie out of Notre Dame who has been inactive for all 14 games, as the only active quarterback under contract. It appears Book is in line for his first regular-season appearance. Running back Alvin Kamara has been the Saints’ emergency quarterback for several seasons and conceivably could take direct snaps as a wildcat threat.

The latest COVID-19 hit to the Saints came as New Orleans awaits the return of Coach Sean Payton, who did not travel to Tampa Bay for the Saints’ 9-0 victory and has worked from home since testing positive for COVID-19 last Thursday. Saints defensive coordinator Dennis Allen has been serving as acting head coach.

Also placed on the COVID-19 list: guard James Carpenter, linebacker Kaden Elliss, safety Jeff Heath, defensive end Jalyn Holmes and defensive tackle Christian Ringo.

Tretter posted on Twitter that he was experiencing symptoms and chose to be tested at the team’s facility in Berea, Ohio.

“Unfortunately, I am positive for COVID-19,” Tretter wrote. “I encourage all NFL players to take every precaution available to them to protect themselves, their families and their teammates from this virus.”

The Browns have been hit hard by a spate of positive tests in the past week and were missing 22 players, including Baker Mayfield as well as Coach Kevin Stefanski, for Monday’s rescheduled game against Las Vegas, which Cleveland lost.

On Wednesday, Tretter spoke to reporters for the first time in weeks and discussed the recent challenges for the NFL and players’ union to navigate the uptick in cases due to the omicron variant.

“It has been a trying week or two weeks for everybody,” Tretter said. “This is a new variant. When COVID first happened, we had six months to kind of figure it out and figure out a path forward. In this instance, we had about six days to figure it out.”

Tretter said he had received the vaccine booster and had chosen to stay away from the facility as the team was conducting meetings virtually. He returned for Thursday’s practice and tested positive shortly before the Browns were scheduled to take the field.

The league relaxed some of its testing policies last week amid the outbreak among the Browns and other teams.

The Browns (7-7), who play at Green Bay on Christmas, got two more players back from the COVID-19 list as linebacker Grant Delpit and rookie offensive tackle James Hudson III were activated. Stefanski returned to the team on Wednesday. Mayfield has yet to produce a required negative test. His 10-day quarantine period ends on Saturday, and it’s possible he’ll play against the Packers despite not practicing.

Also:

• The Vikings added Cook, who already has his third straight 1,000-yard rushing season and is the only player in the NFL with 1,200-plus yards from scrimmage in each of the last three years. Cook has been following protocols for unvaccinated players. Alexander Mattison, who missed the previous game with COVID-19, has returned and will take over the lead role in the backfield.

• Washington’s Heinicke was activated off the COVID-19 list and was back at practice running the offense. Heinicke is expected to start Sunday night at the Dallas Cowboys after missing the game at Philadelphia while in virus protocol along with backup Kyle Allen.

Practice squad tight end Temarrick Hemingway also came off the list. Linebacker Cole Holcomb went into protocol Wednesday, and Washington is preparing to play without him. With so many of Washington’s assistant coaches in COVID-19 protocol, Coach Ron Rivera ran the scout team defense at practice. Rivera remained hopeful cornerback Kendall Fuller and others could be back in time to face the Cowboys.

• Tampa Bay, already struck by injuries as well as the coronavirus, put wide receiver Jaelon Darden and defensive lineman Rakeem Nuñez-Roches on the COVID-19 list. The Buccaneers also placed linebacker Lavonte David and running back Leonard Fournette on the injured reserve.

• Houston placed six more players on the list, bringing its total to 22. Four starters – LT Tytus Howard, C Justin Britt, DT Roy Lopez and safety Eric Murray – were among them. The moves come a day after the team placed top receiver Brandin Cooks and kicker Ka’imi Fairbairn on the list. Houston signed kicker Dominik Eberle to the practice squad Thursday and could elevate him Sunday against the Chargers if Fairbairn can’t play.

• Jets backup quarterback Joe Flacco and right guard Laurent Duvernay-Tardif are the latest placed on the COVID-19 list. The Jets have 20 players on the active and practice squad rosters, including injured reserve, on the list. Coach Robert Saleh also tested positive Wednesday and could miss Sunday’s game  against Jacksonville. Mike White, who was recently activated from the list, will be the backup to Zach Wilson; Flacco is unvaccinated.

Duvernay-Tardif is a licensed medical doctor who opted out last year to fight on the pandemic’s front lines. He’ll likely be replaced on the starting lineup by Greg Van Roten.

• The Falcons will be without defensive end Marlon Davidson against Detroit after he tested positive. Davidson, who had a pick-6 against Tom Brady earlier this month, was on the inactive list for last week’s loss at San Francisco because of an illness.

• The Eagles placed defensive end Ryan Kerrigan on the list and elevated defensive end Cameron Malveaux from the practice squad to the active roster for the Giants game.

• The Chiefs did not have any additional COVID-19 positives on Thursday, and Pro Bowl defensive tackle Chris Jones returned to practice after a positive test caused him to miss last week’s game against the Chargers. The Chiefs still have 10 players on the list, including tight end Travis Kelce and wide receiver Tyreek Hill.

• The Titans will be without left tackle Taylor Lewan, who tested positive.

RAMS: Running back Cam Akers has returned to practice, taking one of the final steps in his rapid comeback from a torn Achilles tendon. The Rams (10-4) designated Akers for return from injured reserve, which means he is in a 21-day window for reactivation to the roster.

Akers was the Rams’ leading rusher as a rookie last season, but he tore his Achilles tendon in private workouts shortly before the start of training camp in July. The team initially expected the second-year pro to miss the entire season, but he made rapid progress in his rehabilitation workouts and spurred hopes he could return late in the year.

Akers racked up 625 yards rushing in 2020 despite not getting consistent playing time until the second half of the season. The second-round pick out of Florida State showed impressive speed and toughness down the stretch and in the playoffs, where he rushed for 131 yards at Seattle and 90 yards at Green Bay, scoring a touchdown in both games.

He was expected to be Los Angeles’ primary running back this season, but the injury led the Rams to acquire Sony Michel in a trade with New England.

Darrell Henderson leads the Rams this season with 671 yards and five touchdowns despite missing three games because of injury, but Michel has been Los Angeles’ most effective back lately, with 292 of his 597 yards coming in the past three games.