When JJ Redick took over as the head coach of the Los Angeles Lakers this summer, he knew just the player he wanted to build around—one of the singular athletes in the sport’s history, a two-way marvel of blocked shots, rebounds and rim-rocking slam dunks. Here’s the twist: It wasn’t LeBron James.

Ever since James packed his bags and headed for Hollywood in 2018, he had been the Lakers’ unquestioned leader. But James will turn 40 years old in December, and in two of the last three seasons, L.A. has failed to win a single playoff series.

So when Redick took the reins of the NBA’s most glamorous franchise, he did something drastic: He gave the greatest player of his generation a demotion.

This season, it has been Anthony Davis, not James, at the heart of the Los Angeles attack.

“It’s our job to empower him on both sides of the basketball,” Redick said of Davis, “to have a monster year.”

Over his first six years in Los Angeles, James was the ultimate boogeyman for Lakers opponents, piling up points en route to becoming the NBA’s all-time leading scorer . But this season, it’s Davis, a 31-year-old center, who leads the Lakers in scoring. Davis also leads the team in shots attempted, rebounds and blocks. His 30.7 points per game are the second-most in the entire NBA, entering Wednesday’s games.

Which means that more and more, James’s primary job is simply to pass the big man the basketball.

“We lean on AD every night,” James said after a recent win over the San Antonio Spurs. “The ball goes through him, not only the first option but also the second option.”

The upshot is that James is now occupying a role he’s never held before: a complementary piece. His 23.5 points per game are the fewest he has put up in more than half a lifetime—since he was an 18-year-old rookie with the Cleveland Cavaliers.

But the most astonishing thing about asking a man nicknamed “The King” to play second fiddle is how well it’s working. With Davis as their cornerstone, the Lakers sit at 10-4. Their offense, which graded out as average last season, is suddenly one of the most potent in the entire NBA, powered by Davis’ hook shots and alley-oop slams.

It helps that James is the rare all-time great known for his willingness to play a supporting role, on occasion, for the good of the team. Michael Jordan played his entire career as the lead option on his teams, and Kobe Bryant kept chucking shots even when his ability to make them waned.

James, to the contrary, has flourished by taking fewer opportunities to score. Recently he tallied a triple-double in four consecutive games—the first such stretch of his decorated career.

“That’s what makes LeBron one of the great ones,” said Robert Horry, a Lakers analyst who, as a player in the 2000s, won three championships with the franchise. “He doesn’t care what happens, as long as the game is played the right way.”

Redick’s plan to turn LeBron James into a sidekick began well before the first game of this season. In fact, it started years before anyone had any inkling that he would ever coach the Lakers. After retiring as a player in 2021, Redick worked for several years as a pundit and podcaster, offering his fixes for various teams—a certain purple-and-gold franchise included.

Before the 2022-23 season, he gave his take on the Lakers. They were a capable team, Redick explained, but they had a problem: Their superstar wasn’t quite the league-destroying force he once was. They would reach their potential only if Davis took over the lead role from James. “This Lakers team becomes a Tier 1 team to me,” Redick said, “if Anthony Davis is A-1.”

Redick had good reason to believe this was the case. For all of his age-defying abilities, James is just six months younger than his new coach—and Redick knew firsthand how the bruises and sprains of a long NBA career can slow a player down.

Davis had also proven that he could take on a greater share of the workload, giving James room to pick his spots and maximize his opportunities.

There had been just one year of the James-Davis partnership when the latter had averaged more points than the former. That was the 2020 season—which ended in the Lakers lifting the Larry O’Brien championship trophy.

When Redick signed on to coach the Lakers, he inherited a team that graded out in the middle of the NBA in offense, and that lacked the draft picks and cap space to add any notable players over the offseason. If the Lakers were going to improve, then, it was going to require thinking outside of the box and managing the resources already on hand better.

The fix was as fast as it was counterintuitive. Redick simply asked one of the greatest players of all time to give up the ball.

Write to Robert O’Connell at robert.oconnell@wsj.com