Column:: Everything hinges on Kawhi Leonard for the Clippers

“Did you see the moving boxes?’’

That’s the first thing you hear when you walk into the Clippers’ draft party Thursday afternoon at a Manhattan Beach hotel.

The talk is not about their two draft picks. It’s not about their promising young players. It’s not even about growing buzz surrounding their new arena.

It’s about a tweet showing a photo of Kawhi Leonard at Toronto’s Yorkdale Home Depot buying moving boxes.

“That’s definitely him! Those are definitely moving boxes!”

Welcome to Stress City, the new Clippers reality as they head into what could be the most important summer of their existence.

With one signature, the long-term future of the franchise could be indelibly changed. Without that signature, their short-term hopes would be brutally dashed.

In two weeks they could be one of the favorites to contend for an NBA championship. Or they could once again be resigned to fighting for a playoff spot. It’s all or almost-nothing, everything swirling around that one signature.

It’s in the giant hand of Leonard, of course, the recently minted NBA Finals MVP, one of the top three players in the world, and the Clippers’ unabashed crush.

He is a potential free agent. He has indicated he wants to return to his Southern California roots. The Clippers are the only team in town with the salary cap space to make that happen. The NBA experts have been saying they are one of the favorites to land him.

The Clippers think they are the perfect spot. They think the quiet superstar would love the lack of drama in their shadowed organization. They think the smart and versatile athlete would relish playing for legendary consultant Jerry West, coach Doc Rivers and a crew that pushed the Golden State Warriors to six games in the first round of the playoffs. They think the basketball entrepreneur would be thrilled to work for creative billionaire owner Steve Ballmer.

They think, they think, they think.

But they don’t know. Those NBA experts don’t know. Nobody outside of Leonard’s close circle knows. Maybe even Leonard doesn’t know.

Usually at this point in late June, the basketball world has some idea about the destination of its available stars, but Leonard owns the league’s most solid poker face, and one of its most enigmatic personalities, and he’s giving no clues.

One minute, he’s waving to Toronto fans who are chanting, “Five more years.’’ The next minute, he’s referring to the Raptors as somebody else’s team.

He’s leaving. He’s not. They have him. They don’t. In two weeks he’s going to be a Clipper. For the next five years he’s going to be a Raptor.

It’s maddening. It’s exhausting. It’s pivotal.

If Leonard signs here, he would become the biggest star in franchise history. The accompanying buzz would pave the way for their new Inglewood arena. They wouldn’t shrink beneath the shine of the LeBron James and Anthony Davis Lakers. It would further legitimize Ballmer as an owner who cares deeply about bringing his resilient fans a winner.

If Leonard doesn’t sign here, well, it would be a loss almost as big as that 19-point blown lead against the Houston Rockets in the 2015 playoffs. It would set them back at least a year while raising an ominous lingering question: If they can’t sign a top free agent now, under these ideal conditions, after spending a year subtly wooing the guy, will they ever attract a top free agent?

The uncertainty surely is driving the Clippers crazy. They have done everything they can to create an attractive home for Leonard outside of publicly begging him, although some would say Rivers already has done just that. But now, like everyone else, they are forced to read the tea leaves with fingers crossed and breaths held.

The only definitive fact working against them is that, because Leonard is already in a Raptor uniform, Toronto can offer him a five-year, $189.7-million contract while the Clippers can offer only a four-year, $140.6-million deal.

But aside from that extra guaranteed year, which the 27-year-old Leonard will probably eventually earn anyway, everything else is a two-sided puzzle.

It would seem bad for the Clippers that Leonard experienced the joy of winning an NBA title with his Toronto teammates while basking in the love of an entire nation. How could he leave that?

But then again, with that title, he might feel he owes nothing more to the Raptors organization that traded for him, and why not attempt to go elsewhere and bring a first championship to another long-suffering team?

The good news for the Clippers is that, in a postgame interview with ESPN after the championship victory, he called it, “Something the Raptors can build on,’’ before catching himself and adding, “That we all can build on.’’

The bad news for the Clippers is that he spent that night dancing in a postgame video that showed his team as family, and how can he leave family?

The good news is that last winter Leonard bought a $13.3-million mansion in San Diego County’s Rancho Santa Fe.

The bad news is that there’s no way he’s driving to Staples Center every night from Rancho Santa Fe.

Tea leaves, people, tea leaves.

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The good news is that Rivers showed Leonard so much love on an ESPN interview, he absorbed a $50,000 tampering fine for it. Who wouldn’t want to play for a coach who says, “He’s the most like [Michael] Jordan that we’ve seen. Like, there’s a lot of great players. LeBron is phenomenal. KD is phenomenal. But he is the most like him.”

The bad news is that, in one of many celebration videos, the Raptors’ Serge Ibaka called Leonard ‘’Fun Guy,’’ which elicited a rare Leonard smile, and he was later seen wearing a T-shirt with the “Fun Guy’’ moniker.

The good news is that on an Instagram video posted by Leonard’s sister Miesha Slayton after the Raptors advanced to the NBA Finals, a background voice screamed, “They know darn well he ain’t going to be there next year.’’

The bad news is that the video was later deleted.

Don’t worry, it will all end soon. Or, heaven forbid, maybe not. Leonard could sign a one-year deal with Toronto while the Raptors still have their championship core, then become a free agent again next summer and put the Clippers through this all over again.

In the meantime, well, there was good news even as recently as Thursday night, when Leonard was seen attending an Angels game and using his phone to videotape Mike Trout.

The bad news was, the game was in Toronto, and Leonard received a standing ovation.

bill.plaschke@latimes.com

Get more of Bill Plaschke’s work and follow him on Twitter @BillPlaschke