NBA commissioner Adam Silver prepared players for a potentially grim landscape amid the coronavirus pandemic, suggesting there are no guarantees when fans could fully return to NBA arenas next season.

Silver said that 40% of the league's revenue comes from money built around game nights in arenas.

"This could turn out to be the single greatest challenge of all our lives," Silver told the players.

ESPN acquired an audio replay of the National Basketball Players Association call, which included Executive Director Michele Roberts, NBPA President Chris Paul and several players asking questions of the commissioner in an hour-long session.

The tone was respectful, but Silver was asked some hard questions about safety issues, return-to-play ideas, how future seasons would be impacted and the financial realities of future salary caps and basketball related income revenues. Silver said that no decision needed to be made on returning to play this season in May, nor immediately into the start of June.

Silver said that "one or two" potential sites for a return to play this season -- including Orlando and Las Vegas -- made the most sense, and that no decision on the league season needed to be made before June.

"There's no point in adding risk for flying all of you city to city if there's not going to be fans," Silver said. "We think it would be safer to be in a single location, or two locations, to start."

Silver allowed that there would need to be some restrictions in place at a single or two-site scenario, but told players: "The goal isn't to have you go to a market for two months to sit in hotel room."

Silver expressed a desire that the NBA complete its season with a traditional playoff structure that includes seven-game series in each round of the playoffs, but left open the possibility of play-in tournaments to accommodate more teams in a shortened season resumption. Silver also told players that the start of next season could be pushed until December, regardless of whether this season was completed or not.

Through it all, Silver reminded players that these were issues that needed to be collectively bargained with the NBPA. Among those issues, he said, included how future BRI and salary caps would be impacted with massive decreases in revenue.

He flatly told players about the current Collective Bargaining Agreement: "The CBA was not built for extended pandemics."

As for a return to play this season, Silver indicated that discussions around training camp length in the resumption of the season centered on a minimum of three weeks. Silver said the NBA's hope would be that players who'd test positive for the virus wouldn't require the shutting down of a team or season, but only the removal of a player amid constant testing of those who had come into contact with him.

Silver expressed confidence that there would be enough mass testing available in the country for the league to feel confident about using such a large number of tests. Once the NBA is ready to play in the next couple of months, Silver said, "We won't be taking tests from needy people."

Sources have told ESPN that the league estimates it would need in the neighborhood of 15,000 tests to resume and complete this season.

Roberts and Paul asked Silver to remind teams that they were not allowed to pressure players to show up at voluntary workouts at team facilities. Silver said, if that was happening, it was "disheartening," and assured them that organizations would be reminded.

"Until there's a vaccine, or some cocktail preventing people from dying from the virus, we are going to be dealing with this collectively," Silver told the players. "The ultimate issue is how much risk we're all comfortable taking."