Before the NBA season started last month, commissioner Adam Silver was asked on a conference call with reporters what it would take for the league to shut itself down again, like it did in March due to the ongoing COVID-19 pandemic.

"I think we are prepared for isolated cases," Silver said. "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."

Less than three weeks later, the NBA's preparation is being tested.

The Philadelphia 76ers on Saturday lost to the visiting Denver Nuggets with only seven healthy players available in the wake of Seth Curry's positive test Thursday night, which ultimately resulted in four of his teammates -- Tobias Harris, Matisse Thybulle, Shake Milton and Vincent Poirier -- being held out for contact tracing as part of the league's health and safety protocols.

Philadelphia's available players kept things close for a half. Ultimately, though, relying on rookies for heavy minutes -- Tyrese Maxey, Isaiah Joe and Dakota Mathias all played over 40 -- proved to be too much to overcome. The issue now for the Sixers, though, is how many times they'll have to play this way.

"I'm looking at our stat sheet, and we have [three guys] at 40-plus [minutes], and it couldn't be avoided," Sixers coach Doc Rivers said. "Now we play again in two days, and then we play again. So that's my concern with this. We got to be very careful in how we navigate over the next week."

Philadelphia is off Sunday then visits the Atlanta Hawks on Monday, followed by a home-and-home with the Miami Heat on Tuesday and Thursday. While the NBA has spelled out a specific return-to-play path for players who test positive, the rules as they apply to players who are identified as close contacts are less clear, with players who are deemed to be a close contact missing varying lengths of time.

The Houston Rockets had their season opener postponed due to most of their team being unavailable between a combination of positive tests and contact tracing. However, they played their next game with several players still out while they completed the league's quarantine process. No other games have been postponed, even if it meant Philadelphia playing with a skeleton roster. And the Sixers aren't the only team facing a growing lack of bodies.

The Boston Celtics have seven players in the protocols as of Saturday night, ahead of their home game against the Heat on Sunday. The Washington Wizards have played three games in the past week -- against the Brooklyn Nets, the 76ers and the Celtics -- against teams that have multiple players out due to the league's protocols.

"We do everything the league gives us; all the memos and the protocols. We do our best," Wizards coach Scott Brooks said prior to Friday night's game against Boston. "We're going to continue to do that. Everybody has been negative, and that's good."

After going through warm-ups, Washington star guard Bradley Beal was removed from Saturday's lineup against the visiting Heat because he was deemed a close contact with Jayson Tatum on Friday night. The two friends who share a trainer guarded each other for significant portions of the game and had a conversation on the court afterward.

Beal being pulled minutes before a game isn't the only close call for the NBA in recent days. Curry sat on Philadelphia's bench for the first quarter of Thursday's loss in Brooklyn before he officially tested positive and left the arena. Memphis Grizzlies center Jonas Valanciunas played in the first half and then was pulled from their game against the Nets on Friday night at halftime due to the protocols, though Memphis coach Taylor Jenkins said afterward Valanciunas hadn't tested positive.

"The numbers are spiking," Heat coach Erik Spoelstra said Saturday night. "That is the reality. We are committed to proceeding with our industry, and we're doing it with all the best science and adherence to the protocols.

"But ultimately, we are not in control."

In these first three weeks of the season, the league is learning that the hard way. One team official asked before the season, half-jokingly, if it would wind up going on a road trip and leave players in one city after another as it went. So far, two teams -- the Chicago Bulls and Dallas Mavericks -- have had to leave players behind; and in another instance, staff from the LA Clippers had to drive back home from Salt Lake City. The Toronto Raptors, who are playing in Tampa, Florida, this season, reversed course on having fans in attendance at games this week due to spikes in the virus.

These are all the things that, as Silver alluded to, both Major League Baseball and the NFL had to deal with in trying to pull off their seasons during the summer and fall, respectively. The NBA, however, is trying to pull this off with far fewer players -- and with COVID-19 raging across the land worse than it ever has, with more than 4,000 people dying from the virus on Thursday alone.

"I think this is something we're going to see throughout the year," Phoenix Suns coach Monty Williams said Saturday, when asked about the situation in Philadelphia.

"I'm sure the league is prepared for what could be a stoppage at some point, if it gets too bad."

During that preseason news conference, Silver was asked specifically about what it would take to stop the season like he did back in March.

"There are not firm numbers on this," Silver said. "The view is I think 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.

"The decision tree that we will look at in terms of suspending the season will be solely a health and safety one. If at any point we no longer believe that it is responsible to play, we will halt the season."

The NBA saw how successful its experiment with a bubble was over the summer. But Silver ruled out doing such a bubble for a full season -- or even a large portion of one -- because of the mental and emotional toll it took on those who were there in Orlando, Florida. Instead, the NBA is forging ahead and playing the season in home markets to allow those in the league to be with their families and to live as normally as possible amid the pandemic.

While Silver has been clear that health and safety have been at the forefront of the league's decision-making process, he acknowledged the economic realities of the situation, saying "tens of thousands" of jobs are dependent on the league continuing to operate.

It hasn't taken long, however, to see how difficult it will be for the NBA to walk that narrow path.

"I do think the reality is that we know this is rampant right now," Celtics coach Brad Stevens said. "And we're doing everything we can, as I've said before, to prevent it, and it's still going to find its way into the league, through travel parties; so we're all assuming some level of risk.

"And I think we accept that and, at the same time, we trust that the people in charge have health and safety as the No. 1 priority; and if it becomes too much, that'll be somebody else's decision who's an expert at it."