New England Patriots quarterback Cam Newton has tested positive for COVID-19, resulting in the postponement of Sunday’s game against the Kansas City Chiefs. John Froschauer/Associated Press

New England Patriots quarterback Cam Newton tested positive for the novel coronavirus and the NFL postponed the Patriots’ game in Kansas City, Mo., against the Chiefs that had been scheduled for Sunday.

The NFL announced Saturday that the Patriots-Chiefs game now is slated to be played Monday or Tuesday and attributed the postponement to positive coronavirus tests “on both teams.” It was the second NFL game scheduled for Sunday to be postponed, with this week’s outbreak on the Tennessee Titans having led to their game in Nashville against the Pittsburgh Steelers being pushed to later in the season.

The league said in a written statement that both teams were working with the league and the NFL Players Association, in consultation with infectious-disease experts, to “evaluate multiple close contacts, perform additional testing and monitor developments.” The NFL also said: “All decisions will be made with the health and safety of players, team and gameday personnel as our primary consideration.”

Newton’s positive test was confirmed by a person familiar with the situation. The Patriots confirmed that one of their players tested positive but did not identify the player.

“Late last night, we received notice that a Patriots player tested positive for COVID-19,” the team said in a written statement released Saturday. “The player immediately entered self-quarantine. Several additional players, coaches and staff who have been in close contact with the player received point of care tests this morning and all were negative for COVID-19.”

The Patriots had been scheduled to travel Saturday to Kansas City but said they had delayed that trip pending consultations with the NFL.

“We are in close consultation with the NFL, as well as our team of independent doctors and specialists, and will follow their guidance regarding our scheduled trip to Kansas City and game against the Chiefs,” the Patriots said in their statement. “The health and safety of our team, as well as our opponent, are of highest priority.”

Newton, the former league MVP for the Carolina Panthers who signed with the Patriots in July, becomes the most prominent NFL player to have tested positive for the coronavirus. He took over for six-time Super Bowl winner Tom Brady, who left the team in March to sign with the Tampa Bay Buccaneers, as the Patriots’ starter at quarterback and was impressive while leading them to two victories in their first three games of the season.

The Associated Press reported that the only known Chiefs player to test positive is quarterback Jordan Ta’amu, a member of the practice squad who has not appeared in a game but would have spent time in meetings with Super Bowl MVP Pat Mahomes and the team’s other QBs.

The NFL previously moved the Titans-Steelers game to Oct. 25 in Week 7 of the season. The league first had said the game would be played Monday or Tuesday, then announced the further postponement after more positive tests results for the Titans. Eight players and eight staff members have tested positive, including three in results returned Saturday.

That was the first postponement of the season as the NFL operates during the pandemic with teams based in their home cities, practicing in their own facilities and playing home games in their own stadiums. The first three weeks of the season were completed with few positive tests and no disruptions to the schedule.

An unidentified player missed his team’s Week 2 game after testing negative but exhibiting symptoms. The Atlanta Falcons’ game last Sunday against the Chicago Bears in Atlanta was played after Falcons rookie cornerback A.J. Terrell tested positive in the results returned the day before the game.

“I think this is something we’ve been preparing for from the very beginning of our preparations,” Allen Sills, the NFL’s chief medical officer, said in a phone interview Friday, before Newton’s positive test and the Patriots-Chiefs postponement. “As we’ve said repeatedly, we expect to have new positive cases. No matter how careful everyone is or how stringent our protocols are, as long as this disease remains endemic in our society, it’s going to be extraordinarily difficult, if not impossible, to avoid any new positive cases.

“So that’s why our focus has never been on elimination of the virus because we just know that’s medically impossible. Instead, we’ve focused on mitigation, which means when we do have a positive case, that we try as best as possible to prevent spread within any of our team communities or our league as a whole. The events of this week are exactly why we planned and put the protocols in place that we have. We had a plan and a preparation there to walk through when this unfolded.”

The Titans’ facility remains closed and Sills said Friday it will not be reopened until the league is “convinced that we’ve reached the end of the transmission event that occurred earlier this week and that we have put in place all the measures to keep everyone safe there.”

The Minnesota Vikings, who played the Titans last Sunday in Minneapolis, reopened their facility Thursday under enhanced health and safety protocols. The Vikings again had no positive tests in testing results returned Saturday, according to a person familiar with those results. The Vikings have had no positive tests this week and the NFL plans for the Vikings-Texans game to be played as scheduled Sunday in Houston.

NFL players, coaches and certain team staffers are tested daily for the coronavirus, except on game days, under the protocols developed by the league and players’ union. After the outbreak on the Titans, the league informed teams of enhanced protocols for teams experiencing an outbreak or exposed to one. Those protocols include daily point-of-care tests in addition to the regular testing, including game days; and a mask-wearing requirement for players, along with coaches and staffers, while on the practice field.

The enhanced protocols say that players on those teams also should wear gloves while on the practice field, with the lone exception being a quarterback’s throwing hand. Players are prohibited from gathering away from a team’s facility, under the enhanced protocols.

The league and NFLPA have extended their regular daily testing indefinitely. That testing program now covers players and coaches while teams are on their bye week. The NFL has imposed heavy fines on head coaches and teams – of $100,000 per coach and $250,000 per team – for violations of its directive that coaches and staffers must wear face coverings properly while on the sideline during games. Players are not required to wear masks while on the sideline during games except for in a couple selected cities in which that’s required under local guidelines.

The NFL previously has left open the possibility of switching to a “bubble” format, like the NBA did with all teams gathered at a single site in the Orlando area, for the postseason. Some experts believe the NFL should consider having teams require players, coaches and staffers to stay in a hotel instead of going home from the team facility every night.