CNN  — 

Covid-19 has become the main opponent of several professional leagues and university sports programs as teams are forced to change their game plan in the face of positive tests or coronavirus exposure.

The cancellations and postponements are the latest disruption in the US due to the increased spread of Covid-19, as many athletes are being asked to quarantine due to league protocols.

Sports aren’t alone. Broadway has also been affected.

Here’s a look at the changes to the sports schedule:

NHL pauses season until after Christmas

The National Hockey League said Monday that after two games on Tuesday, it would pause the current season until after Christmas Day.

All four of Wednesday’s games had already been postponed before the league and the players’ union opted to suspend operations. Ten of 15 games Thursday had already been postponed.

Games are scheduled to resume December 27.

On Sunday, the NHL and NHLPA had announced the regular-season schedule would continue but that effective Monday all games involving cross-border travel between the US and Canada would be postponed through Thursday.

With Monday night’s announcement, there now have been 49 games postponed, 44 of them since December 13.

Because of the disruption and concerns about the pandemic, the statement said “the NHL and NHLPA are actively discussing whether players should participate in the 2022 Beijing Olympics.”

NFL postpones three games for a few days

The NFL is postponing three Week 15 games due to Covid-19 issues around the league, the league announced Friday.

Saturday’s scheduled game between the Cleveland Browns and the Las Vegas Raiders was rescheduled for Monday at 5 p.m. ET.

The decision comes after 23 Cleveland Browns players have landed on the NFL’s Covid-19/Reserve list in recent days, including the team’s starting quarterback Baker Mayfield. Browns coach Kevin Stefanski also tested positive for the coronavirus earlier this week.

“While our team and entire organization diligently prepared for tomorrow’s game as initially scheduled, both from an on-field and fan-experience standpoint, we respect the NFL’s decision to postpone our matchup against the Raiders,” the team said in a statement from chief spokesperson Peter John-Baptiste.

Sunday’s scheduled games between the Washington Football Team and the Philadelphia Eagles and between the Seattle Seahawks and Los Angeles Rams will both be postponed until Tuesday. Both Tuesday games will kick off at 7 p.m. ET.

As of Friday, the Rams had placed 29 of its players on the Covid-19/Reserve list. The Washington Football team has 23 players on the Covid-19/Reserve list, including its first- and second-string quarterbacks.

“From the outset of the coronavirus pandemic, our focus has been to play our games in a safe and responsible way, consistent with the best available medical and public health advice, based on protocols jointly developed and implemented with the NFL Players Association,” Commissioner Roger Goodell wrote in a memo to each team.

The NFL describes the Covid-19/Reserve list as being for players who either test positive for Covid-19 or who have been quarantined after having been in close contact with an infected person or persons.

NFL teams not are permitted to comment on the medical status of players other than referring to roster status. Clubs may not disclose whether a player is in quarantine or is positive for the virus.

NBA postpones five games

The National Basketball Association has announced the postponement of five games due to Covid-19 issues within several teams in the league.

The Brooklyn Nets, Cleveland Cavaliers, Orlando Magic, and Philadelphia 76ers each have large portions of their rosters and other team staff in the NBA’s Health and Safety protocol.

Sunday’s scheduled games between Nets the and the Denver Nuggets as well the Cavaliers game against the Atlanta Hawks and the 76ers versus the New Orleans Pelicans were postponed.

Monday’s game between the Magic and the Toronto Raptors was also postponed, as well as Tuesday’s game between the Nets and the Washington Wizards.

No details were provided about rescheduling of the affected games.

NCAA teams postpone games or find new opponents

The NCAA men’s basketball calendar has been turned upside down with more than a dozen games canceled or postponed in recent days.

Most notably, games between No. 2 Duke and Loyola and between No. 4 UCLA and North Carolina scheduled for Saturday have been canceled due to Covid-19 issues within the UCLA and Loyola programs, the schools announced Friday.

Duke and UNC found new opponents. The Blue Devils’ first scheduled foe, Cleveland State, announced some positive tests results and Loyola was set to step in but some of its players got Covid-19. Now Duke will play in-state rival Elon University.

Duke and UNC found new opponents. The Blue Devils’ first scheduled foe, Cleveland State, announced some positive tests results and Loyola was set to step in but some of its players got Covid-19. Duke instead played in-state rival Elon University Saturday, winning 87-56.

The Tar Heels will play the Kentucky Wildcats in Las Vegas, who had been scheduled to play Ohio State in the same arena at the CBS Sports Classic.

Two other men’s top 25 games have been canceled. No. 16 Seton Hall was to play Iona, but officials said the game cannot be played because of Covid-19 protocols at Seton Hall.

Seton Hall also will forfeit Monday’s Big East Conference game against St. John’s, the league announced. While the forfeit counts as a conference loss, it does not affect the Pirates (9-1) overall total number of losses.

No. 23 Colorado State canceled its games against Tulsa on Saturday and against No. 6 Alabama on Tuesday because the 10-0 Rams have “Covid-related concerns.” The games will not be made up.

In women’s basketball, No. 19 Kentucky’s game against Morgan State, which has Covid-19 issues, was postponed.

The University of Miami will forfeit Sunday’s Atlantic Coast Conference game to No. 15 Duke.

CNN’s Kevin Dotson and Alaa Elassar contributed to this report.