The conga line of NBA expansion groups is longer than anyone realized, especially in Las Vegas, where they’re placing $8 billion cards on the table.

“It’s music to my ears,” NBA Commissioner Adam Silver said during this week’s board of governors press conference.

If the song he’s hearing is Viva Las Vegas, it’s a perfect fit. According to Silver, there are more potential ownership groups in Vegas than the five who’ve already announced themselves. And as for the other possible expansion city of Seattle, Silver said Kraken and Climate Pledge Arena majority owner Samantha Holloway has similarly been joined by multiple unidentified bidders.

“Most of the groups that are interested have not been public,” Silver said. “So I wouldn’t conclude that because there aren’t other public groups coming forward, that therefore there isn’t other interest in Seattle. There is. And I would also say the same in Las Vegas. Some groups have been public. The majority of groups have not been public. So stop there on that portion.”

What is known, according to sources involved in the bidding, is that the NBA expects to have at least a 31st franchise by the 2028-29 season — and that Las Vegas is a likely “yes” and Seattle could be a “yes,” “a maybe” or a “no.” And if Las Vegas does wind up as the 31st franchise, it will be a most prescient development.

As he often has in the past, Silver said this week that the Las Vegas Summer League has “in essence, operated as our 31st team for 22 years.” In fact, even though the NBA will be the last of the major sports to place a franchise in Sin City (behind the Golden Knights, Raiders and A’s), the league was the first to take players there through Summer League. At the time — circa 2004, with the slot machines and sportsbooks nearby — it was considered risky, unethical business.

But while there have been ups and downs for the league in the city over the years — such as the NBA Cup exiting Las Vegas next season for in-market semifinals and a final at Butler’s Hinkle Fieldhouse — this year’s Summer League was perhaps the busiest ever.

Part of it might have been the deep rookie draft class, which included a head-to-head opening night matchup of No. 1 AJ Dybantsa versus No. 2 Darryn Peterson, plus similar debuts from No. 3 overall Cameron Boozer and No. 4 overall Caleb Wilson. So summer in Las Vegas has not only turned into the NBA’s version of MLB’s winter meetings, it’s literally become a tentpole event.

This year, for instance, behind lead operators Warren LeGarie and Albert Hall, Summer League staged a film festival, a student enrichment program and a sales training platform. Silver said the league set all-time attendance, merchandise and social media records. But behind the scenes, a main topic of board of governors meetings there was the city’s expansion free-for-all.

Indications are that there are two early leaders for the Las Vegas franchise. One is the Las Vegas Jacks group, fronted by former Suns owner and Basketball Hall of Famer Jerry Colangelo; ex-player and former Suns executive Vinny Del Negro; former Turner president and ex-Nets executive David Levy; former Duke and Bulls guard Jay Williams; and Prime Capital Financial Chair and Managing Partner Scott Colangelo (no relation), who put the consortium together.

The second-most formidable group is fronted by former Disney CEO Bob Iger and Thrive Capital founder Joshua Kushner. Both they and the Las Vegas Jacks have one purported advantage: ironclad financing in the vicinity of $8 billion (the Jacks have a $12.5 billion to $13 billion asset target) at a time the league is seeking bids between $7 billion and $10 billion.

A third group, led by Golden Knights owner Bill Foley, is an intriguing option as well, mainly because he has a 15% stake in T-Mobile Arena (AEG and MGM Resorts International split the rest) and could house the team temporarily in 2028-29 while his group puts up roughly $300 million to renovate the facility. That said, the sense from sources is that Foley may ultimately fold his bid into one of the other two top groups.

But make no mistake: The league wants a new NBA arena in Las Vegas — probably the No. 1 item on Silver’s expansion to-do list. Sources said there are open lots near the luxury Fontainebleau on South Las Vegas Boulevard; near the Mandalay Bay resort on South Las Vegas Boulevard; and near the Rio Hotel & Casino on Flamingo Road. Whoever wins the bid could play temporarily at T-Mobile (AEG and Co. could rent it out before an arena gets built).

Silver and league strategic adviser PJT Partners are likely to ask the following questions to bidders: Is your money secure? Where is your arena? Where is your practice facility? Who’s going to do the financing for the team? Who is your lead governor? Who is going to be the governor the commissioner ultimately reports to? All of those things will resonate with the board of governors when it ultimately votes on an ownership group by the end of this year.

The same priorities stand for Seattle, which hasn’t had an NBA franchise since 2008, although Holloway’s crucial advantage is that she and the umbrella she operates under — One Roof Sports and Entertainment — owns Climate Pledge Arena. No one expects a building to be constructed there, although there are so many unknown bidders and so much big tech money there, you never know.

“I think Seattle, we had an incredibly successful Sonics team there for years,” Silver said this week. “It’s an amazing market. We do a lot of business with Amazon and Microsoft. It’s probably the A.I. capital of the world right now.”

But that’s the point — bidders are “coming out of the woodwork,” one source said. Keep in mind this is the first NBA expansion process since the then-Charlotte Bobcats in 2004, so the bidders, or at least the ones from Vegas, see this as a once-every-quarter-century opportunity:

Turn Las Vegas summer league into Las Vegas winter league.