As a new wave of Covid-19 sidelines dozens of NFL players, the league on Friday announced three weekend games were rescheduled for later next week.
"We are seeing a new, highly transmissible form of the virus this week resulting in a substantial increase in cases across the league," the NFL said in a statement.
Saturday's Las Vegas Raiders-Cleveland Browns game has been moved to 5 p.m. ET Monday.
Sunday's Washington Football Team-Philadelphia Eagles and Seattle Seahawks-Los Angeles Rams games were pushed to 7 p.m. ET Tuesday.
The disruption came as the Browns did not practice Tuesday or Wednesday and added eight players to its reserve list Friday as a result of positive Covid tests, the NFL said. Offensive assistant coach T.C. McCartney has also tested positive, it said Friday.
The Browns have 21 players, including many of their starters, on the list.
On Thursday, the Los Angeles Rams put nine players on its list of those who have tested positive, bringing the total number of players on their Covid list to 25.
The Washington Football Team reported Friday that two players did not participate in practice as a result of illness; it has at least 21 players on its Covid list. Quarterback Taylor Heinicke was among its players who have tested positive, according to NFL Network reporter Ian Rapoport.
The Eagles did not practice Wednesday, the league said. The team has two players on its Covid-19 list.
The Raiders did not practice Tuesday or Wednesday and reported at least one player out on Friday as a result of illness, according to the league.
New Orleans Saints head coach Sean Payton tested positive and will not participate in its game Sunday, Rapoport said.
In a memo to team executives Friday, NFL Commissioner Roger Goodell said additional games could be rescheduled or even canceled.
"The emergence of the omicron variant is precisely the kind of change that warrants a flexible response," Goodell wrote.
On Thursday, the league announced new pandemic rules have added to its Covid-19 protocols. They include "masking regardless of vaccination status," no outside visitors during away games, conducting meetings outdoors or remotely and the elimination of communal meals, according to a statement.
"We will continue to strongly encourage booster shots as the most effective protection," the NFL said.
Infections in pro sports have also triggered game postponements for the NBA and NHL.