After a conference call with the NBA on Tuesday night, the National Basketball Coaches Association told ESPN its full membership is prepared to participate in the upcoming NBA season despite high rates of coronavirus infection and spread in many parts of the country.

"As we enter the season, all of the protocols and daily testing and travel reduction leave us feeling that we've taken the proper precautions to be as safe as possible," NBCA president and Dallas Mavericks coach Rick Carlisle told ESPN on Tuesday night. "That said, we know there are many more variables this season and we'll need to be flexible and able to pivot quickly."

The NBA's health and safety protocols for the upcoming season mandate all coaches, including head coaches, wear masks at all times while coaching -- a change from the in-game mask policy used during the league's summer restart in Orlando. The guidelines warn that coaches "must not regularly pull down their facemasks more than is occasionally necessary under the circumstances to perform essential coaching duties."

The NBA and NBCA also agreed to continue the practice of more casual game attire, no longer requiring coaches to wear sports jackets, sources said. Coaches voted more than 2-to-1, sources said, to allow for wearing polo shirts in games. Coaches must wear business attire, such as dress shirts, pants, socks and shoes, sources said. The NBA will disallow sweat-pants and jogging pants.

Most arenas will start this season without fans. The league approving the polo look has the potential of a polo staff facing off against a suit staff -- a stylistic clash that concerns some coaches, and will be the subject of more conversation between the coaches association and league.

"There is a visual extreme," Carlisle told ESPN in August. "One staff looks like they are at a wedding, and the other looks like they are about to tee off."

It is expected that there would be a coordination of attire, but those are still scenarios that'll be worked out between now and the start of the season on Dec. 22.

As the NBA leaves the bubble environment to travel and plays its games in team arenas, there are no longer concerns among older coaches in the league that they could be restricted from participating in the season. Ahead of the NBA's summer restart in a bubble at Walt Disney World Resort, the league created a medical review process in which an independent panel could flag anyone deemed high risk of serious coronavirus infection -- and then unilaterally prohibit that person from attending in Orlando.

Several 60-and-older coaches feared the policy would end up targeting them, jeopardizing their participation in the restart and even their future employment opportunities, sources told ESPN at the time. Age has been considered one risk factor, among many others, for worse coronavirus outcomes. Under the league's guidelines for the Orlando restart, every participant -- players, coaches, staff -- was subject to the medical review, which considered pre-existing health conditions and other risk factors beyond age.

Despite that broader purview, employment law experts told ESPN the review process and unilateral prohibitions on attendance could run afoul of employment discrimination laws. Several argued that in setting up what turned out to be a secure bubble, the NBA had reduced risk to the point that the choice of attending should be left up to individuals.

"I hope there is a basketball solution to this rather than a legal one," Warren Legarie, a prominent agent for coaches -- including Mike D'Antoni (69) and Alvin Gentry (66), then the head coaches of the Houston Rockets and New Orleans Pelicans -- told ESPN in July.

The medical review process did not end up excluding anyone who wished to attend.

In the lead-up to the 2020-21 season, the dynamic has largely flipped. After setting up that medical review process for Orlando, the NBA is leaving the decision of whether to participate in the coming season -- which will not take place in a bubble -- to each individual. Teams will be playing in home arenas, traveling from city to city on planes, and staying in hotels.

The NBA's health and safety guidelines state that if a coach or staff member elects to withdraw from the season, the decision of whether and how to compensate that person will be up to his or her team. (There is a separate process, crafted via collective bargaining between the league and players union, for any player who wishes to withdraw. They will receive some portion of their salary.)

Last week, the NBA and the National Basketball Players Association announced that a round of testing of 546 players in the last week of November returned 48 positive tests. The New York Knicks and Portland Trail Blazers recently shut their practice facilities for short periods due to positive tests within their organizations. The Golden State Warriors and Toronto Raptors also revealed the existence of positive tests within their organizations this week.

The NBA has gone to great lengths to make this season's set-up as safe as possible. Last week, they released a 154-page health and safety guide for the season. The document includes instructions for frequent testing; how to safely distance and eat on planes; where players can eat on the road and who can accompany them; how teams should be isolated from other guests and housekeeping staff at hotels; and many, many more such protections.

Players and members of each team's 45-person traveling party will now be tested twice daily, sources tell ESPN. One test will be the standard nasal swab PCR test that returns results within 24 hours. On top of that, the NBA has added a rapid-return PCR test that can provide results in 30 minutes -- and has proven to be more accurate than rapid-return antigen tests that have been in use for several months, sources said.

Teams are beginning group practices this week. Preseason games begin Friday. The regular season opens on Dec. 22.