The Tennessee Titans suspended in-person activities through Friday after the NFL says three Titans players and five personnel tested positive for the coronavirus, becoming the first COVID-19 outbreak of the NFL season in Week 4.

The outbreak threatened to jeopardize the Titans’ game this weekend against the Pittsburgh Steelers and posed the first significant in-season test to the league’s coronavirus protocols.

The NFL issued a statement Tuesday saying both the Titans and Minnesota Vikings suspended in-person activities Tuesday following the Titans’ test results. The Titans beat the Vikings 31-30 in Minneapolis last weekend.

“Both clubs are working closely with the NFL and the NFLPA, including our infectious disease experts, to evaluate close contacts, perform additional testing and monitor developments,” the league said.

A person familiar with situation told The Associated Press the eight test results were all confirmed positives, making this the first outbreak since the season began on Sept 10. The person spoke to the AP on condition of anonymity because of health privacy regulations.

The Vikings released a statement saying they had not received any positive results from their testing after Sunday’s game against the Titans and followed NFL protocol by closing their facility immediately. They will remain closed at least through Wednesday. They also scheduled a video conference call for Wednesday morning with GM Rick Spielman and head athletic trainer Eric Sugarman, who is in charge of the team’s COVID-19 protocols.

Minnesota is scheduled to visit Houston (0-3) on Sunday.

The Titans (3-0) are scheduled to host the Steelers (3-0) on Sunday in a matchup of two of the league’s seven remaining undefeated teams. With the Titans unable to practice until Saturday at the earliest, when that game might be played is unknown.

“I just wanna play,” Titans starting left guard Rodger Saffold tweeted.

“All decisions will be made with health and safety as our primary consideration,” the NFL said. “We will continue to share updates as more information becomes available.”

Commissioner Roger Goodell sent a memo to teams Tuesday noting the protocols set up by the league and the NFLPA are being followed. Those who tested positive will be isolated, monitored and offered medical care, and family members also are offered testing. Officials and others who worked the game will be tested.

“This is not unexpected; as Dr. Sills and others have emphasized, there will be players and staff who will test positive during the season,” Goodell wrote in the memo obtained by The Associated Press, referencing the NFL’s chief medical officer, Dr. Allen Sills. “We are exploring in more detail the nature of the close contacts to determine where they occurred (locker room, flights, etc.), and identify any additional learnings that can be shared with all clubs.”

Goodell asked NFL teams to look at what they’ve done to limit contact, especially when traveling and within position groups, and to review how they bring in players for tryouts. He noted the test results confirm the need to follow health and safety protocols “to the fullest extent.”

The NFL has been fining coaches and teams for coaches seen not following the league rules requiring face coverings during games.

Pittsburgh coach Mike Tomlin pushed back his usual Tuesday news conference six hours trying to get some answers, and he said he didn’t have many when he talked to reporters.

“We’ve been given a mandate to prepare as if the game is going to be played and played on time, so that is our mentality,” Tomlin said.

Tomlin also has no concerns about going to Nashville to play the Titans as scheduled either.

“We’re going to trust the medical experts,” Tomlin said. “If they deem it safe for us to proceed, we’re going to go down there with the intention of playing and playing to win.”

Steelers defensive tackle Cam Heyward wrote on Twitter that the guys playing the next week now wind up affected.

“This is wild but this is the world we live in now,” Heyward wrote.

The Titans initially announced Tuesday morning that they would be working remotely “out of an abundance of caution” after several test results came back positive. They beat the Vikings in Minneapolis without outside linebackers coach Shane Bowen, who did not travel with the Titans following a test result Saturday.

Coach Mike Vrabel said Monday that Bowen was not with the team. Rookie offensive lineman Isaiah Wilson, their top draft pick out of Georgia, also has been on the reserve/COVID-19 list for the Titans since Sept. 6.

“It’s been in Ohio as early as the mid-1850s at least, brought in as an ornamental plant because of its unique foliage and white flowers,” Gardner said. “It was actually planted in people’s landscaping, and it has been spreading.”

The Titans use devices that detect whenever someone is within 6 feet of another device and records how long they are that close together. That provides a recording of everyone’s interactions from inside the team headquarters to the practice field, an airplane, inside a hotel and at a stadium.

That information should help the Titans and the infectious disease experts know which players and coaches were at risk. With the Titans’ facility now closed for four days, that should also help limit further spread of the virus.

The Titans were due to have about 7,000 fans in Nissan Stadium on Sunday as local restrictions eased, expanding to about 8,500 on Oct. 11 for a game against Buffalo and up to 10,000 on Oct. 18 when Houston is scheduled to visit.