The theory states that the most popular person in many NFL cities is the backup quarterback. For the sake of discussion, let’s change the sport to basketball.

Now imagine if that backup is a beloved local kid who has won big at every level and received a hero’s welcome back to town.

Godspeed, Ricky Rubio.

“This is a big-boy league,” Flip Saunders noted.

Yes, the NBA is not for the faint of heart or mind, and the Timberwolves’ incumbent point guard will get a dose of that reality in what already felt like a crossroads season.

Once upon a time, Rubio was the toast of the local sports scene, a young, charismatic novelty with flair to his game.

Now, he’ll get to hear how great Tyus Jones is every day.

Jones hadn’t even finished hugging his relatives after learning that his pro career will begin in his hometown before giddy social media users started with “Trade Rubio” nonsense.

You can picture the reaction from some fans the first time Rubio posts a 2-for-12 shooting performance.

Let’s all take a deep breath and slow down.

Jones just turned 19 in May. He needs to develop his body and adjust to the NBA game. It’s a luxury for him to learn the ropes behind Rubio, 24, without being thrust into a starter’s role.

Jones is a proven winner who seems immune to the effects of nerves. But this situation allows him to develop at his own pace.

That’s all assuming Rubio avoids injury and plays well. Things would become interesting in any other scenario.

Jones joins the Wolves as a favorite son, a hoops prodigy raised under a spotlight at Apple Valley. Nobody embraces provincialism like we do.

That’s something Rubio will have to deal with, in addition to proving that he can stay healthy, make a jump shot consistently and lead a young roster.

“I’m sure he’ll handle it well,” Saunders said. “He’s been in a lot of pressure-type situations. Competition is great.”

This marks a pivotal season for Rubio on the heels of a lost season. The Wolves still can’t say with clarity what they have in him, and Saunders’ dogged pursuit of Jones provides an interesting subtext.

Saunders worked hard to get Jones on his roster after watching and studying him closely for years. He loves Jones’ composure, the way he shines in big moments and how he thrives in pick-and-roll situations.

Saunders has constructed a nucleus of talented youngsters and he clearly has a plan for Jones, which adds even more urgency to Rubio’s fifth season.

“It’s a critical year for every player,” Saunders said, “but when you’re a young player … usually after your fifth year, that’s who you are.”

Rubio has shown flashes of brilliance when healthy. He’s a creative passer, a hard-nosed competitor, a disruptive defender and someone who plays with passion and takes losing personally.

Those are his best qualities.

But a “when healthy” qualifier remains attached to him until proven otherwise. An ankle injury limited him to a career-low 22 games this past season. He shot the ball poorly when he was available.

Rubio has encountered his share of tough luck with injuries, which is unfortunate, but that’s become part of his narrative. In that regard, having Jones on the roster could prove valuable.

A segment of fans have soured on Rubio, but the organization has invested time and money (four-year, $55 million contract) in him so it’s worth more patience to determine whether he can reach his full potential.

Another disappointing season and the conversation changes.

Jones faces his own challenges as the hometown kid. He grew up before our eyes, always king of the court.

He was one of the nation’s best prep players at Apple Valley, where he won a state title. He was one college basketball’s best players at Duke, where he won a national title.

We really haven’t seen him struggle. Nothing guarantees that continues.

“I know there are big expectations, a lot of pressure, being from here,” Jones said. “But that’s how I want it. I’m ready for it and I’m accepting it.”

The spontaneous euphoria of fans on draft night will subside eventually, but the homegrown attachment won’t, and that creates a unique starting point for a rookie.

And for the guy he’s backing up.