The bubble kept the NBA safe from the coronavirus. The real world will be much tougher.

That didn’t quite happen with the NBA, which cleared out of Disney World in mid-October and never looked back. Within weeks, the league and its players’ union began negotiating the financial terms, schedule and structure of the 2020-21 season. Even though the pandemic raged on and has reached new peak levels this fall, returning to the safety of a bubble to start the season was never seriously considered.

Both sides were motivated to apply lessons learned from the bubble, which they viewed as a successful but arduous stopgap, in crafting a solution that would more closely resemble a typical season. Rather than hoping for the pandemic to wane or delaying the start of the season to wait for a vaccine, the owners and players sought a plan that would return the league to its normal calendar for the 2021-22 season next fall, when the national health situation should be improved.

“The owners wanted their arenas back, and the players wanted their lives back,” said an Eastern Conference executive, who, along with other executives quoted in this story, spoke on the condition of anonymity to freely discuss the upcoming season.

Indeed, finances and personal freedom were among the chief drivers of the NBA’s plans. In interviews, front-office executives from several teams said their owners wanted to be in position to safely welcome fans back into their buildings as quickly as possible to recoup revenue losses, which they said totaled 10 percent in 2019-20 and could reach 40 percent in 2020-21. Meanwhile, the players had little interest in extending the isolated bubble environment — which restricted access to their families and the outside world — across a full season, especially in light of mental health concerns.

With both sides seeking to limit the financial damage to the league, they made several compromises.

First, they would rush through an abbreviated offseason and play a truncated 72-game schedule. The regular season and playoffs would take seven months, and the schedule would be split into two parts to account for the possibility of postponed games.

Finally, they would use home arenas rather than a neutral site. Teams would return to cross-country travel, although they would cover fewer total miles by playing consecutive games in the same market when possible.

“The goal isn’t zero positive tests [during the season],” an Eastern Conference executive said. “That’s not realistic. The goals are creating safe environments and quickly identifying cases [to prevent uncontrolled spread].”

To accomplish those goals, the NBA issued teams a 158-page health and safety protocol that features guidance from the Centers for Disease Control and Prevention and many of the same rules that governed life at Disney World. One key difference from the bubble is a decentralization of responsibility. In the bubble, the NBA made and enforced the rules, set up a massive testing program, operated three arenas and covered all transportation needs. Outside the bubble, teams will be responsible for educating, testing, monitoring and transporting their players, as well as managing, cleaning and disinfecting arenas and practice facilities.

To carry out those duties, teams were required to “identify and designate” staffers for a long list of new roles: infectious-disease specialist, infection-control specialist, rapid testing coordinator, testing officer, testing managers, contact tracing officer, contact tracers, protocol compliance officer, face mask enforcement officers, player liaison, facility hygiene officer, arena health manager, health education officer and travel safety officer.

“Are we ready? I don’t know,” a Western Conference executive said last week. “I’m exhausted. I know that.”

According to the protocols, players must report to their teams in small groups, undergo regular testing and fill out a daily health questionnaire before teams can assemble for full practices. Players are banned from taking public transportation and using ride share services, and they cannot make in-person promotional appearances until at least Jan. 22. Teams must jump through numerous hoops, including obtaining approval from the league for their dining areas before they can serve group meals. The NBA has the authority to “[conduct] periodic unannounced in-person inspections of team facilities” to “ensure each team’s compliance,” and it has warned teams that violations that affect scheduled games could trigger fines, suspensions, the loss of draft picks and forfeited games.

If a player tests positive, he must remain in isolation for at least 10 days or pass coronavirus tests on two consecutive days before receiving clearance to return. The preseason begins Friday, and there already have been significant virus-related setbacks. During the first wave of preseason testing, 48 of 546 players were positive. Multiple positive tests over the past week led the Golden State Warriors to postpone the start of individual workouts and the Portland Trail Blazers to close their practice facility Sunday. And the Toronto Raptors were forced to relocate to Tampa after the Canadian government refused to give them permission to host games.

During media day interviews last week, prominent players expressed a range of opinions on playing through the virus. Dallas Mavericks guard Luka Doncic said the title chase would be influenced by which team doesn’t have people test positive. Kawhi Leonard told reporters that his Los Angeles Clippers were hoping to build better chemistry but noted that the virus could make it more difficult to bond off the court.

Minnesota Timberwolves center Karl-Anthony Towns, whose mother died in April after contracting covid-19, revealed Friday that he had lost six other family members to the disease caused by the coronavirus. “I’ve seen a lot of coffins in the last seven or eight months,” he said. “It’s going to be hard to play. It’s going to be difficult to say that [basketball] is therapy. I don’t think this will ever be therapy again.”

Brooklyn Nets guard Kyrie Irving released a statement declaring he wouldn’t participate in media interviews because of the pandemic’s wide-ranging effects. “Life hit differently this year, and it requires us, it requires me, to move differently,” he said, risking a possible fine from the league office.

The NBA’s media access plan calls for strict restrictions on reporters, who can attend games but must remain away from the court and outside the locker room. Executives from numerous teams said their regional television broadcast teams would not travel for road games at the beginning of the season. All player interviews will be conducted virtually, and practice facilities will be closed to the media.

Owners and team executives remain consumed by the challenge of getting fans back into their buildings. Anthony S. Fauci, the director of the National Institute of Allergy and Infectious Diseases, told Yahoo Sports last week that returning full capacity to sports stadiums probably won’t happen until “the end of the summer” — after the 2021 NBA playoffs are complete.

Whether teams will be able to host fans at all in the meantime will vary from city to city, and it could change from week to week based on the spread of the virus. In November, San Francisco officials rejected the Warriors’ plan to host games at half-capacity. The Lakers and Clippers were among numerous teams to preemptively announce they would open the season in empty buildings, and the Cleveland Cavaliers announced Friday they would host 300 fans at their home games, per Ohio’s current regulations.

“You have to plan for no fans, limited capacity, and then look at it with a longer-term mind-set when you can build toward a full building,” said Portland Trail Blazers team president Chris McGowan, whose organization will open without fans. “We’re focused on making the arena experience safer [with enhanced] sanitation protocols, contactless payments, ticket processing and communicating the basics like washing hands. When fans can come back, they’re going to know we’re ready.”

Medical officials from multiple teams said they have studied the NFL’s and MLB’s approach to the coronavirus, as well as best practices at high-traffic public places such as airports. Still, they expressed concerns about the daunting task of limiting the spread of the virus in a variety of environments, including homes, arenas, facilities, planes and hotels.

In the bubble, one player was forced to quarantine after he strayed off campus to pick up a food delivery; another was held out of a playoff series for inviting an unauthorized guest to his hotel room. Strict enforcement of those rules was deemed necessary because basketball is an indoor sport in which players spend hours in close contact.

This season, players will be banned from visiting bars, nightclubs and public gyms, and at their hotel rooms they will be limited to two guests, who must be family members or close friends. Teams will be able to use only preapproved restaurants and private dining spaces on road trips. Still, regular contact with the outside world will be inescapable, dramatically increasing the risk of spread within a team.

“There are so many entry points into an organization,” said Robby Sikka, the Timberwolves’ vice president of basketball performance. “Until we’ve traveled, we can’t know all of them exactly. Families, particularly young kids in schools, are an entry point. Another is overconfident people who think the virus can’t impact them or that there aren’t long-term consequences. This is also a virus that leads to shame. We can’t have people who hide [if they develop symptoms]. Those are challenges.”

Other sources of apprehension among team officials include the long-term physical and cognitive effects of covid-19 on athletes; the lack of a clear standard for what will lead to a game being postponed; and the regularity with which NBA players find themselves in higher-risk situations such as locker room conversations.

As multiple companies prepare to distribute the first round of coronavirus vaccines, teams aren’t counting on a magic bullet. Early in the pandemic, the NBA was heavily criticized when its players received access to coronavirus tests that were scarce at the time. Since then, the league has made a point to use private companies, rather than public resources, for its testing. Officials from multiple teams said they don’t expect their players — who are generally at lower risk, given their age and fitness — to receive access to vaccines during the first few months of the season, at minimum.

The league’s focus entering the season, according to people with knowledge of the situation, is to establish workable day-to-day procedures rather than pinning its immediate hopes on the vaccine, which isn’t 100 percent effective and could require weeks to administer with multiple shots. The NBA and NBPA do have plans to discuss vaccines and whether players will be required to get one if it has proved to be effective, once the Food and Drug Administration has given its approval.

Among the new rules, increased health threats and logistical challenges, the NBA is heading into a season that will be far more complicated than the bubble. The owners and players agreed to take on these challenges because, as one team executive put it, “we have no choice but to get back up and running.”

Facing the possibility of $4 billion in lost arena-related revenue this season, league and team decision-makers are focused on customer retention. Extended disruptions to relationships with season ticket holders and regional sports network subscribers could lengthen the time it takes to get back to the steady economic growth the NBA enjoyed before the pandemic.

The league’s rush to return this month, then, is as much about laying groundwork for the future as it is about establishing normalcy in the present.

“I’m still very bullish on the NBA,” McGowan said. “[After the pandemic], I think we get back to being more popular than we were prior to the pandemic. The NBA is a global game, and it’s well positioned internationally. The worldwide celebrity of our players isn’t going away. Hopefully we’re able to look back on this as a massive challenge but a short-term one in the grand scheme of things.”