NBA commissioner Adam Silver on Friday said his personal preference is for the play-in tournament to continue after this season, and that it was a success because of the incentive it gave teams to care until the end of the regular season.

"I haven't made any secret that I want it to be [around long term]," Silver told Keyshawn, J-Will and Zubin on ESPN Radio. "I have two constituencies I need to convince of that. One is the 30 teams, and I think for the most part they've supported it. Again, I understand the sentiment if I were a team -- a 7-seed in particular -- the notion [that] after a long season, you could potentially play out of the playoffs. I understand those feelings. I think at the same time, the teams recognize the amount of additional interest we've created over the last month of the season plus those play-in games make it worth it.

"Of course, the other constituency is the players. For example, one player, who is on the executive committee of the union, said to me yesterday that he really likes the play-in tournament but he felt it could potentially be a bit unfair. For example, if you were the seventh seed and you were a significant number of games ahead of the 8-seed, the notion that you could somehow lose two games and be out of the playoffs seems unfair."

Silver said it's possible the league will tinker with the format, which this year saw the seventh- and eighth-place teams play for the No. 7 seed, with the loser then hosting the winner of a game between the ninth- and 10th-place teams for the No. 8 seed.

He said the additional interest the play-in has provided has been a big success, and that the NBA and other entertainment properties need to "earn your viewers every day."

While the regular season was shorter, Silver said it was the incentive structures that the play-in tournament provided that made it a compelling way to play out the final weeks of the regular season.

"Over the past few years, pre-pandemic, there's been a lot of reference to our long regular season and the issues around player resting, and we tried to address that as well," Silver said. "We moved to a 72-game season because of the pandemic and somewhat condensed so we had 10 fewer regular-season games, and I had hardly heard a mention about it. ... I think the way we dealt best with the resting, although we have some rules around it now, was the motivation for teams to care about being in the playoffs and their actual play-in position.

"That incentive is what made the biggest difference, not the reduction of the 10 games."

Out of the 30 NBA teams, 24 had a chance to earn a spot in at least the play-in tournament over the final two weeks of the regular season.

"I'm going to wait only because I know there's people on both sides of it," Silver said. "... Beyond the individual ratings, and some games have been pretty good and some haven't been as close, but putting aside those games and adding those games to our schedule and the amount of interest in them is where I think the play-in tournament had an impact. [It] was causing teams who frankly otherwise may have thrown in the towel some number of weeks back to fight for those last playoff spots."

Meanwhile, as cities across the country ease restrictions on movement and gathering as the number of vaccinations for COVID-19 increases, Silver stopped short of committing to completely full arenas by the time the NBA Finals roll around in July.

And while seats around the court will remain in fewer numbers than normal, he expressed confidence that there will be far more fans than he expected in the seats as the playoffs move along.

"I think it's very possible that come July, when our Finals will be, you'll see essentially full buildings," said Silver, who added that "close to 80%" of all NBA players have had COVID-19 vaccinations.

Reiterating comments he made during All-Star Weekend in Atlanta, Silver said the NBA will attempt to restart its season in mid-October, allowing the league to return to its traditional calendar that sees the season run until late June, when the NBA Finals typically take place.

"We're going to have to do a shorter offseason -- a bit of a shorter offseason -- if we're going to get back on schedule," Silver said. "Because if we start late and then go late again obviously into next summer, this will just continue.

"And we think in terms of fan interest, in terms of what our television partners are telling us, that we're better off completing our Finals by the end of June."

Silver said the only realistic way the league could start on Christmas, as some have suggested it should do, would be to shorten the regular-season schedule. In his opinion, this year hasn't offered evidence that the league should do that.

"We've looked at other lengths of the regular season, and we will continue to do so," Silver said. "At least based on the evidence from this season, I don't think that's a strong argument to go to fewer regular-season games. And look, it's not a secret, obviously it's a business. That's a reduction in revenue.

"I think the benefit of reducing the number of games ... one, it would go to player health, and see whether a lot of science around that in terms of the amount of rest and the number of minutes and how impactful that is. And the other issue is, you have fewer games. Does it make each game that much more valuable? On the other end of the spectrum, of course, is the NFL, where each game has so much value that, if you're a fan, you're not going to take a game off as a viewer or attending the game. So those are all things we're continuing to look at."

Silver also addressed why the league fined Atlanta Hawks coach Nate McMillan ahead of the Hawks' playoff series against the New York Knicks, which starts Sunday. McMillan said that the NBA "wants" the Knicks in the playoffs and that "there's going to be a lot of calls that probably won't go our way" vs. New York.

"Nate's a veteran coach and he knows better," Silver said. "He's trying to inspire his team to try and suggest the league would somehow prefer some teams over others, and it's just not the case. He knows it, and he's just got a young team and wants to get them going."