Bitterness consumed Mr. McLean for a while, and he left sports for a decade to focus on mastering a new career in finance. He began managing the assets of normal, unable-to-dunk people, but before long, some of his old Arizona teammates enlisted his help. They knew he was good with money, and they knew he could be trusted with theirs. And because he was a former athlete, one who’d come within an eyelash of the N.B.A. himself, he knew what made them tick.

Mr. McLean understood that athletes, the special ones anyway, are goal-oriented. They want to be pushed, they want to be coached. It started to dawn on him that this was his path, at long last, back to the N.B.A.

$5,000 a week to cut grass

The top stars in every American pro sport make gobs of money. Mr. McLean also has clients in the N.F.L. (Jameis Winston, Whitney Mercilus), Major League Baseball (Nolan Arenado, Dexter Fowler) and the P.G.A. (Sergio Garcia), but the gobs are the biggest in the N.B.A. The league-average player salary is nearly $10 million, compared with about $3 million in the N.F.L. James Harden, the N.B.A.’s best-paid player, will make nearly $50 million in the 2022-23 season.

All those riches attract opportunists, and some outright crooks. “The guys are much smarter now,” Mr. McLean said. But players still get conned. Recently, the Lakers point guard Lonzo Ball sued a family friend, accusing him of siphoning $1.5 million from an apparel company Mr. Ball’s father had started. Far more common is garden-variety exploitation — overcharging, skimming off the top, dumb deals done in good faith.

Last summer, after Mr. Gordon signed his $84 million deal, he bought a house and was immediately confronted with all kinds of mundane homeowner questions for which he had no answers. Such as: How much should it cost to mow my lawn?

“The first couple people that came to the property were sending these invoices trying to charge $4,000 to $5,000 a week to cut grass and do some power washing,” Mr. McLean said. Mr. Gordon has a big house, but not that big — it should have cost around $500. “So I’ve got to go back to Orlando and get people that we trust on the property. I’ve got to speak to everyone that goes near it, because they’re all signing N.D.A.s.”

“The power of paying the bills,” he added, “is seeing when someone’s trying to exploit them.”