An NFL preseason game between the Seattle Seahawks and the Las Vegas Raiders at Allegiant Stadium on August 14, 2021 in Las Vegas, Nevada.

Ethan Miller | Getty Images

As Covid cases surge, professional sports leagues are once again feeling the impact, leading to postponements and star players missing games.

More than 100 individuals throughout the National Football League, National Basketball Association, and National Hockey League entered health and safety protocols this week.

The NFL alone had more than 70 players test positive for Covid cases on Monday and Tuesday, and is on pace to surpass the 72 positive cases the league reported on Dec. 2 for the period between Nov. 14 and Nov. 27. Seven teams are now in enhanced mitigation protocols, which require more testing and stricter prevention rules. In addition, a staff member with the Washington Football Team tested positive for the recently discovered omicron variant, which which world health officials say is spreading faster than any other Covid strain.

Although leagues are unlikely to press the panic button like in March 2020, when the NBA led the complete suspension of sports games, the rise of the omicron variant is causing concern.

Here’s where leagues stand after Covid outbreaks this week.

Freeport, N.Y.: Close-up shot of a Pfizer COVID-19 vaccine booster shot being administered in person’s arm as the Mount Sinai South Nassau Vaxmobile vists Freeport High School, in Freeport, New York on November 30, 2021.

Steve Pfost | Newsday | Getty Images

NFL mandating booster shots

The NFL is tightening up its Covid guidelines as it nears the end of its regular season and prepares for its first playoff rounds next month before the Super Bowl LVI on Feb. 13 in Los Angeles.

An NFL memo sent out on Monday and seen by CNBC stated tier 1 and tier 2 team staff, including coaches and front office personnel, must receive the booster shot by Dec. 27.

At the same time, star players, including Rams receiver Odell Beckham, have been placed on the Covid list, sending the teams into more intense protocols. After positive tests, the Rams joined the Atlanta Falcons, Cleveland Browns, Minnesota Vikings and Washington Football Team in the league’s enhanced protocols. The guidelines force all players to endure daily testing, hold virtual team meetings and enforce mask mandates. Per league rules, individuals who test positive are isolated, not permitted in team facilities, and can’t have direct contact with players or personnel.

“We continue to have discussions with our medical experts and the NFLPA,” said NFL spokesman Brian McCarthy in an email to CNBC Wednesday morning. “As we did last year, we remain adaptable and flexible and will make changes based on the latest guidance to ensure the health and safety of everyone associated with the NFL.”

The NFL laid out punishments for outbreaks that lead to game cancellations or postponements last July. It warned teams could be required to pay any shortfall to the visiting team’s pool of gameday revenue or even forfeit games. Players would also miss game checks.

Despite the penalties, some NFL teams and players made the headlines for violating NFL Covid policies this season.

Earlier this month, the league suspended Tampa Bay Buccaneers wide receiver Antonio Brown and two other players for three games without pay for lying about their Covid-19 vaccination status. And last month, Green Bay Packers star Aaron Rodgers apologized for misleading the league about his vaccination status.

Rodgers tested positive for Covid and was also fined $14,650 for attending a party while unvaccinated, and the Packers were fined $300,000 for their violations.

The NFL is holding an owners’ meeting in Dallas this week, and league commissioner Roger Goodell is expected to further address the league’s Covid outbreak on Wednesday afternoon.

Bam Adebayo #13 of the Miami Heat greets Zach LaVine #8 of the Chicago Bulls after the game at FTX Arena on December 11, 2021 in Miami, Florida.

Michael Reaves | Getty Images Sport | Getty Images

Covid could ruin NBA’s momentum

Meanwhile, NBA commissioner Adam Silver predicted the league would see additional positive cases when he spoke at a sports conference last October. 

So far, he’s correct.

On Monday, the NBA postponed two games featuring the Chicago Bulls following a Covid outbreak that impacted 10 players. The Bulls had the required league minimum of eight players available to play, but after discussions with Chicago health officials, the NBA ultimately decided to reschedule the Bulls home game at United Center.

NBA protocols mandate players sit out at least 10 days or produce two negative tests in 24 hours before returning.

In addition to the Bulls, the Brooklyn Nets also had seven players, including All-Star James Harden, enter health and safety protocols. The Milwaukee Bucks could also be without their star Giannis Antetokounmpo due to Covid, and the Los Angeles Lakers were cautious after a recent positive test. 

The NBA notes 97% of the league is vaccinated, and behind the scenes, there’s an estimation of more than 60% who received the booster shot.

Still, positive Covid cases could threaten the NBA at a crucial time.

The league has highlighted its viewership success this season ahead of its annual Christmas Day games next weekend. But those contests could be a lot less appealing if star players are out.

One of the Christmas games the NBA is banking on next Saturday is the Brooklyn Nets versus Los Angeles Lakers on Disney-owned ABC. Cryptocurrency exchange Crypto.com is also relying on that contest, as it marks the official debut of its $700 million arena naming rights pact with the Lakers.

The league is in contact with clubs to request available dates to plan for more postponements, and there’s speculation the NBA could start to require proof of booster shots among media members with access to players.

But there’s no indication if the NBA is ready to consider more extreme measures, like suspending courtside and lower bowl ticket sales. That would eliminate proximity to players and staff, which could help reduce the risk of Covid transmission, but would hurt attendance revenue and deal a blow to the league’s $10 billion projection this season.

“Like the rest of the country, and as was predicted by our infectious disease specialists, we have seen an increases of cases around the League,” said NBA spokesman Mike Bass in a statement to CNBC. “As we have since the pandemic began in March 2020, we will continue to follow the science and data and will, in close partnership with the Players Association, update our protocols as deemed appropriate by our medical experts.”

The NBA could get help from local governments, too. More cites are mandating that fans show proof of vaccination before entering arenas. And local mandates could also cause unvaccinated players to get vaccinated or risk losing game checks.

Hockey has also been affected. The NHL delayed a game in Chicago after the Calgary Flames suffered a Covid outbreak. The team was scheduled to play the Blackhawks on Monday

It’s the third time this season the NHL postponed a game due to Covid. The New York Islanders contest in Philadelphia on Nov. 30 was also postponed after an outbreak on their roster.