Is the sun setting on Klay Thompson?

The gulf between Steph Curry and Klay Thompson has never been wider. In their primes, Curry was the alpha, but Thompson was right behind him. In recent years, injuries have accelerated Thompson’s career clock and we may be seeing the effects reach critical mass. En route to Golden State’s 130-119 loss to the Phoenix Suns, Curry poured 50 points on 28 shots, adding six assists, and nine boards. Curry has been sipping from the fountain of youth, dissecting defenses built to obstruct him, and still managing to create buckets at an otherworldly rate. Thompson looks prehistoric.

So much of the offseason conversation revolved around Draymond Green, that Thompson’s slippage was glossed over. The vibes were different with Thompson so the expectations were more bullish than they were for Green. He’s chill, he sails, he rides bikes, and his brand is better. ESPN is even writing about Klay’s “epic comeback.”

This season he’s shooting 35 percent from the field, sinking below the league-average 3-point percentage (35 percent) — and he’s more ornery than ever. Before the season, Thompson repeatedly lambasted NBA2K’s rating adjuster Ronnie 2K about his 3-point shooting rating being an 88. He might have been too generous.

Here’s how the players ranked behind Thompson on 2K have shot the 3-ball this season.

• Klay Thompson (88) — 33 percent
• Jayson Tatum (88) — 36.4 percent
• Luke Kennard (87) — 46.7 percent
• Devin Booker (87) — 36.4 percent
• Donovan Mitchell (87) — 42.6 percent
• Damian Lillard (87) — 38 percent
• Tyrese Maxey (87) — 40.8 percent

The last time Thompson and the Warriors were waxed by the Suns, Klay was ejected and reminded Devin Booker of his four rings. Against Phoenix, Thompson looks like his sun may be setting.

In his first clash with the Suns on Oct. 25, Thompson was 1-for-8 from the floor before being ejected. On Wednesday night, he shot 6-of-17 from the field, scoring 19 points, but continuously rushed shots in transition and was downright slothful on defense. Thompson earned bonafides as a 3-and-D wing, but now he’s got neither. His front-rimming open triples and his shooting percentages are down in every zone.

Curry’s absolute masterclass in the first month of the season has deflected from Thompson’s deterioration. However, the more Thompson struggles to get his shot back on track, the larger the elephant in the room will grow. Thompson has endured cold streaks before, but they’re occurring more frequently, and last longer, and the highs aren’t so high and the lows are even lower.

Klay has heard the chatter and he’s been unhappy about it, telling Bleacher Report this week, “I feel like I deserve more credit for battling through all that injury shit. I helped a team win a championship last year and people still want to discredit what you do.”

The clamoring for Jordan Poole to replace Thompson in the starting lineup has already begun in earnest. However, their Big 3 starting unit is still the NBA’s most formidable, and Thompson has played only 22 minutes all season without Curry in the lineup. They’re attached at the hip for now.

Golden State’s youngsters off the bench were considered untouchable in the offseason, but that was when the championship goggles had Golden State believing they’d forged a Duncan-to-Kawhi-like transition. There’s a forward in Brooklyn right now who has expressed passionate opinions about his lack of help who could use a stable partner. Absent a Durant-Curry reunion, Golden State’s solution isn’t as binary as benching Thompson or moving him to the bench.

Steve Kerr discussed adjusting his rotation last week, but the obvious move is staring him in the face. Thompson’s legs don’t have the juice they used to, so why not cut his minutes in the regular season? The distribution of playing time between the 23-year-old Poole and Thompson, 32, is paradoxical to common sense unless Kerr is afraid of Thompson’s response.

Poole is Golden State’s Christopher Walken’s cowbell; they need more of him. In his 28.5 minutes per game, he’s exhibited boundless energy and his productivity is in line with last season’s, but after his contract extension, he should be playing more minutes so that Thompson can play fewer.

If the Warriors are going to win another championship, it may not be with Thompson in his current role.