WHAT JUST happened to the Utah Jazz is the nightmare scenario that no Sixers fan wants to contemplate.

After seven seasons, All-Star forward Gordon Hayward has left Utah as an unrestricted free agent and signed with the Boston Celtics.

It's a great move for Boston, which now becomes a legitimate challenger to the Cleveland Cavaliers as the top team in the Eastern Conference.

For the Jazz, however, it is a crippling blow that leaves one of the rising young teams in the Western Conference in a state of uncertainty.

The scary thing if you are a Sixers fan - or a fan of any team that is diligently trying to build - is that Utah has fallen dramatically without doing anything wrong.

As a matter of fact, the Jazz did just about everything right to go from a 39-43 team in 2010-11, the season after it drafted Hayward ninth overall out of Butler, to a 51-31 squad that won the Northwest Division and advanced a round in the playoffs in 2016-17.

Through shrewd trades and drafting, Utah built a young core of Hayward; All-NBA second-teamer and Defensive Player of the Year runner-up Rudy Gobert; rising power forward Derrick Favors and shooting guard Rodney Hood.

After those players developed, Utah brought in veteran point guard George Hill, big man Boris Diaw and shooting guard Joe Johnson to push things to the next level.

Now Hayward, 27, is taking his 21.9 points, 5.4 rebounds and 3.5 assists to Boston.

It didn't matter that Jazz management put a talented roster around him or that Hayward was beloved by Utah fans.

Management was prepared to over him a maximum contract worth nearly $170 million over five years. In fact, the Jazz has hoped that Hayward would have qualified for a super-max contract because it then could have offered him a six-year deal worth around $200 million.

Still, Hayward thanked the Jazz and Utah fans for seven great years and then accepted what is reported to be a four-year deal worth $128 million from Boston.

The money was not the primary driving force.

Hayward made a personal decision, and personal decisions are the wild card that no team or fan can prepare for.

Humans make decisions based on internal motivations that cannot be accurately predicted.

LeBron James accepted less money and left Cleveland to win rings for his legacy. With titles in hand, he returned to Cleveland to fulfill the promise of a championship that he did not deliver the first time.

Kevin Durant left a good situation and more money in Oklahoma City to successfully chase a championship with Golden State. He is now taking way below market value to help the Warriors stay in a position to remain on top.

Only the individual truly knows what pushes the right buttons, and that brings us back to the Sixers.

They are doing things a lot like Utah did in acquiring young talent with high potential.

By comparison, the Sixers, with Joel Embiid, Ben Simmons, Markelle Fultz and Dario Saric, has a young core with more potential than Utah had at a similar point.

The Sixers appear to be doing it right, and through the NBA collective bargaining agreement have the ability to hold onto each of those players for seven years, like the Jazz did with Hayward.

That might seem like a long time, but considering how young most top draft picks are, they'll reach their prime as players just about the same time they can elect to become unrestricted free agents.

That's when it gets tricky because once the player has complete control, there are no guarantees for the team.

What if Embiid's injury history makes the Sixers hesitant about offering a maximum extension by the end of October?

Embiid is eligible for a five-year extension worth around $150 million. That's huge risk for someone who has played 31 games in his first three seasons.

If the Sixers don't give Embiid that and he suffers no further injury, would he hold that against them when he is due his third contract and the Sixers won't have a right of first refusal?

Would he decide more money isn't enough to stay with a franchise that did not show complete faith in him?

Even if the Sixers did give him all the money, there is no assurance it would buy his loyalty. You can't predict what a player's mindset will be four or five years down the road.

At some point, perhaps just as the Sixers are on the verge of ascending to the highest level, Embiid, then Saric, then Simmons, then Fultz will have the opportunity to become unrestricted free agents when they are around 27.

That's the reality of the NBA. The Sixers could do everything right to build an upper-echelon team, and one day, through no fault of their own, it could fall apart because of the whims of one or two players.

Just ask the Utah Jazz about what happened with Gordon Hayward.

smallwj@phillynews.com

@SmallTerp