Faced with a rise in positive coronavirus tests among players that led to four postponed games since Sunday, the NBA instituted significantly stricter health and safety protocols as it seeks to continue playing through the pandemic.

In the latest round of measures, which were discussed with the National Basketball Players Association this week, the NBA is instructing players to restrict all nonessential activities during homestands and to remain in their hotels while on road trips. Players will be expected to avoid public settings other than playing games and attending practices, and they will no longer be allowed to eat at approved restaurants or host personal guests at their hotel rooms, as they had been under the league’s initial health protocols.

The new rules require players to wear masks on the bench and in the locker room, while coaches and other team staffers must wear their masks “at all times during games.” Philadelphia 76ers Coach Doc Rivers was fined $10,000 for repeatedly lowering his mask during games this month.

The NBA is also seeking to limit contact between opposing players in an attempt to reduce spread from team to team. Players from opposing teams will be prohibited from embracing and making close-contact encounters before and after games. Washington Wizards star Bradley Beal was forced to quarantine this week after embracing Boston Celtics star Jayson Tatum, who later tested positive, after a game.

Meanwhile, pregame team meetings in the locker room will be limited to 10 minutes, and masks are required for all attendees. All other team meetings must be held in a socially distanced manner.

During flights between markets, teams must use a new seating chart procedure “so that players whose assigned seats are closest to each other on the bench for games are also closest to each other on the team plane.”

These rules would go into effect for two weeks, at minimum, as the NBA tries to make it through January, which has seen coronavirus case counts and deaths reach new highs nationally. The NBA said this weekend it had no plans to pause its season, which began Dec. 22, because of positive tests.

In recent weeks, the NBA adjusted its protocols to require players to wear masks on the bench before they checked into games and to wear proximity sensors that track their contacts in the case of a positive test. Despite those changes, the NBA has postponed five games this week, including three involving the Boston Celtics, because teams were unable to reach a minimum benchmark of eight active players. Only one game during the season’s first two weeks, a season opener between the Houston Rockets and Oklahoma City Thunder, was postponed.

The new health protocols would simplify the NBA’s investigations of players who are caught on camera in public settings. Rockets star James Harden was fined $50,000 in December for appearing at a social gathering without wearing a mask. The NBA is also investigating a video of Brooklyn Nets star Kyrie Irving attending a large indoor gathering without a mask that surfaced Monday. Irving has not appeared in the Nets’ past three games, and the Nets said in a statement that he “remains away from the team due to personal reasons” and his return date is not yet known.

“We are reviewing the circumstances with both Kyrie and the NBA in order to determine compliance with health and safety protocols,” Nets General Manager Sean Mark said in a statement, confirming that the organization was “aware” of the video.

After a perfect health track record in last year’s bubble, numerous players have been isolated or quarantined recently because of positive tests or recent exposure, including Nets star Kevin Durant, Tatum, Beal, Denver Nuggets forward Michael Porter Jr. and at least four members of the Dallas Mavericks. The Wizards were forced to cancel practice Tuesday after two players were placed into the health protocol, and then Wednesday’s game against the Utah Jazz was postponed.

“I’m for whatever the NBA wants us to do,” Wizards Coach Scott Brooks said Tuesday before the Jazz game was postponed. “We have to always focus on the safety of our players and staff and family, and that’s more important to me than playing a game. If we have to cancel a game or pause, I’m for whatever we have to do. I’m for it, and our players feel the same way.”

Commissioner Adam Silver hasn’t established clear criteria for what would need to happen for the NBA to put all of its games on hold. The league released its 2020-21 schedule in two parts to allow flexibility to make up postponed games.

“If we found a situation where our protocols weren’t working, meaning that not only did we have some cases of covid but that we were witnessing spread either among teams or even possibly to another team, that would cause us to suspend the season,” Silver said in December. “I think we are prepared for isolated cases. In fact, based on what we’ve seen in the preseason, based on watching other leagues operating outside the bubble, unfortunately it seems somewhat inevitable. But we’re prepared for all contingencies.”

Ava Wallace contributed to this report.