The NFL may be up against its most serious COVID-19-related challenge yet, as a potential outbreak has caused two teams to suspend in-person club activities for the week. According to Tom Pelissero of the NFL Network, the Tennessee Titans had three new player positives and five new personnel positives for COVID-19. Then on Wednesday, it was learned one more Titans player tested positive on Tuesday, bringing the total number of positive tests to nine. All other tests for both the Titans and the Vikings came back negative, however.

Later Wednesday morning, the league announced that the game between the Steelers and Titans would be postponed, and will likely be rescheduled for next Monday or Tuesday. Titans coaches have told players that they will be prepared to face the Steelers, even if they are unable to physically meet as a team until Saturday's walkthrough, according to NFL Network's Mike Garofolo.

Since the Titans played at the Minnesota Vikings on Sunday, both teams suspended all in-person club activities starting Tuesday. According to ESPN's Dianna Russini, a league source said on Tuesday that they are "shutting Tennessee down until Saturday," which means no Titans coaches or players can be in the building. Following this report, the Titans released a statement confirming that they had received multiple positive tests.

"Out of abundance of caution, the organization has decided to work remotely today as we follow NFL protocols related to the COVID-19 virus. Several tests have come back positive and (we) are working through the process of confirming them. We will have more information tomorrow."

The NFL and NFLPA released a statement of their own, saying that both the Titans and Vikings are working closely with the league to weather this potential storm. 

"On Tuesday morning, the Titans COVID testing results returned three new player positives and five new personnel positives. The Titans will suspend in-person club activities starting today. Likewise, the Vikings, who played the Titans on Sunday, will also suspend in-person club activities. 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. All decisions will be made with health and safety as our primary consideration. We will continue to share updates as more information becomes available."

On Tuesday afternoon, ESPN's Adam Schefter shared a copy of the email that NFL commissioner Roger Goodell sent to team presidents and executives. Goodell says that the players and staff members who have tested positive are being isolated and carefully monitored. The league has also reviewed contact tracing data which includes members who worked the game in Minnesota last Sunday as well as the officials from the matchup. The NFL is exploring in more detail the nature of the close contacts to determine where they occurred and identify any additional learnings that can be shared with all clubs. 

"That's one thing about being a pro," Titans tight end Jonnu Smith told CBS Sports Radio's "Tiki and Tierney" on Tuesday. "We've been doing it all offseason with these zoom meetings, so we're kind of used to the flow of things."

He added: "I don't know what the league is going to do or what they're going to decide, but if we are playing, we're going to be prepared, stay in shape, and most importantly, stay quarantined."

The Titans said that they will need to "confirm" the positive tests since the league has already dealt with an abundance of false positives this offseason. Back in August, a total of 77 positive tests for COVID-19 came back to 11 teams. After further review, it was concluded that these were false positive tests, and all of the original tests were rerun with each sample coming back negative for the coronavirus. Jon R. Cohen, M.D., the Executive Chairman of BioReference Laboratories, the testing partner of the NFL, released a statement explaining that these false-positives were due to an isolated contamination in the New Jersey lab. 

"We have been in contact with the NFL regarding the positive COVID-19 tests with the Tennessee Titans," the Steelers' statement read, per Mike Garafolo of the NFL Network. "We have been informed to proceed with our game preparations for Sunday's game until we are informed otherwise. We will provide more information when it becomes available." 

Both the Steelers and Titans enter Week 4 undefeated on the young season at 3-0, so whenever the game is able to be played, it should be a good one.