Commissioner Gary Bettman is eager for the NHL to resume playing games after the season was suspended due to the coronavirus pandemic, but only if the players are physically fit.
"We don't want them playing games until they're back in game shape," Bettman told the NHL Network on Thursday.
Bettman also said the end of the current season, whenever that happens, could push back the beginning of the 2020-21 season to December.
"This isn't a race to be the first back," he said adding there is no definite timetable for a restart.
"We're going to try to make good, prudent, careful judgments. When we come back, we want it to be at the right time, for the right reasons, under the right circumstances.
"We have a great deal of flexibility in terms of when we can start. There's no magic for next season of starting in October as we traditionally do. If we have to start in November or December, that's something that will be under consideration."
The regular season was originally set to end on 4 April.
The NHL shut down on 12 March due to the global coronavirus pandemic. When the season was halted, the clubs had played three quarters of their 82 regular-season games.
Bettman, the owners and the players' union have formed a working group called the Return to Play Committee which is laying the groundwork for the return.
He said the NHL plans to reopen some of its team training facilities as early as mid-May in areas where stay-at-home and social-distancing restrictions are working.
"We're going to continue to monitor things, and when the guidance from the medical people is right and the governmental authorities are comfortable, then we'll take step one, which is reopening our training facilities," he said.
Eight NHL players are known to have tested positive for Covid-19, including five from the Ottawa Senators.