The NFL has fined several Las Vegas Raiders players after it was revealed they failed to follow league and local health guidelines by going maskless at a recent charity event; and now commissioner Roger Goodell is threatening teams with potential forfeits for COVID-19 protocol violations.  

In a memo sent to the teams Monday after a conference call involving NFL and club executives, Goodell reiterated the need to adhere fully to all of the league's health and safety guidelines.

'Protocol violations that result in virus spread requiring adjustments to the schedule or otherwise impacting other teams will result in additional financial and competitive discipline, including the adjustment or loss of draft choices or even the forfeit of a game,' Goodell wrote in the memo obtained by the Daily Mail.

'Simply put, compliance is mandatory. Now is the time to recommit ourselves to our protocols and best practices for the duration of the season.'

The Associated Press was the first to report the memo.  

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The NFL was forced to reschedule Sunday's game between the Steelers and Titans when Tennessee had the league's first coronavirus outbreak, which has affected 20 organization members, including 10 players. That game was moved to Week 7, causing adjustments that also impacted the Baltimore Ravens.

And New England's game at Kansas City was moved from Sunday to Monday night after Patriots quarterback Cam Newton tested positive for COVID-19, as did a Chiefs practice squad player.

Goodell noted that violators of the protocols have been disciplined. 

Several coaches, including the Raiders' Jon Gruden, have been fined $100,000 each and their clubs fined $250,000 for improper use of face coverings. Meanwhile the Raiders were fined $50,000 for allowing an unauthorized team employee into the locker room following a game and on Monday.   

A person familiar with the punishment said Monday that the host of the event, Raiders tight end Darren Waller, was fined $30,000 and his teammates were docked $15,000 each for their actions at last week's fundraiser for his foundation. The person spoke on condition of anonymity because the punishments weren't announced by the league.

NFL Network first reported the fines.

Among the players seen in attendance were quarterbacks Derek Carr and Nathan Peterman, tight ends Jason Witten, Foster Moreau and Derek Carrier, receivers Zay Jones and Hunter Renfrow, cornerback Nevin Lawson, offensive lineman Erik Magnuson, and Waller.

'I'm well aware of that, yes,' coach Jon Gruden said Monday. 'I know our players are going to handle them individually. I know they regret any harm they may have caused. They're very sensitive about it and we'll handle it the right way. I'm going to reiterate, I'm really proud of our players and our staff and the job that we've done battling this virus, and it'll continue.'

Players were seen without their masks mingling with guests, who also didn't have face coverings. The city of Henderson fined the DragonRidge Country Club $2,000 for four violations of the Nevada governor's COVID-19 emergency directives, including people not wearing masks and more than 50 people at the event.

'We tried our best even at the event with everything, and we weren't perfect but we were trying our best,' Carr said last week. 'We weren't trying to be careless or reckless.'

The event raised $300,000 for Waller's foundation that helps young people overcome drug and alcohol addiction.

This is just the latest punishment handed to the Raiders for violating COVID-19 protocols this season.

'Complacency is our shared opponent,' Goodell wrote in the memo.

'The consequences of rescheduling or even missing games are obvious. Our fans will be deprived of games. Competitive inequities will be introduced into our season. Players will not be paid for games not played and clubs will similarly suffer financial consequences.'

The league and the players' association are instituting ramped up health and safety procedures in the wake of the Titans' outbreak, including:

• A longer onboarding process for free agent tryouts;
• Bans on gatherings outside of the club facility;
• Limitations on the number of tryouts permitted per week;
• Implementation of a league-wide video monitoring system to ensure compliance with the protocols - 'particularly the mandate that all staff and players wear PPE while in a club facility and on travel at all times.'

The league also is considering holding all meetings virtually; requiring masks or shields during practices and walk-throughs; decreasing the size of the traveling party to games; reducing the time spent in lunchrooms and locker rooms; and daily consulting of proximity tracking device information now in use to identify areas where teams could eliminate close contacts.

'As we have said before,' Goodell wrote, 'act as if every person you come in contact with has a COVID infection and take appropriate precautions.'

The Titans' outbreak reached 20 cases on Sunday, the team's sixth straight day of at least one positive, with 18 returned since Tuesday. But Tennessee got no positives back Monday morning, a person with direct knowledge of the test results said, speaking to the AP on condition of anonymity because neither the NFL nor the Titans announced the latest results.

Tennessee will need continued negative results to host Buffalo (4-0) on Sunday, and Wednesday is the earliest the Titans can get back inside their facility as long as they have back-to-back days of negative test results.

Titans linebacker Will Compton wrote on Twitter: 'No positive tests. Victory Monday.'

The negative test results returned Sunday included New Orleans Saints fullback Michael Burton, who falsely tested positive on Saturday. The Saints learned of the positive test after leaving New Orleans for Sunday's scheduled game in Detroit and ran another series of tests on players and staff overnight.