The Golden State Warriors fell apart on Sunday against the Brooklyn Nets, crunch-time once again proving the difference in a 120-116 loss. Here are three key reactions from another major missed opportunity for the defending champions, just a few days after collapsing late to the Boston Celtics.

Awful crunch-time collapse

The Warriors led the Nets 110-98 with 5:42 left on the back of an awesome game-long effort from their bench.

Jonathan Kuminga might have been Golden State's best player against the Nets. Kevon Looney was stellar in his new reserve role for the second straight game, and Donte DiVincenzo's two-way energy was contagious. Golden State's second unit of Jordan Poole, DiVincenzo, Andrew Wiggins, Kuminga and Draymond Green—a very intriguing combination—completely changed the game in the fourth quarter, building on an impressive first half effort.

But the Warriors were outscored 22-6 from there, anemic offensively and unable to stop Brooklyn on the other end as Kerr searched for workable lineups. The ones he settled on left Klay Thompson guarding Kyrie Irving for many late-game possessions, a matchup that went about as well as it did from the opening tip despite Thompson's best efforts.

 

There's no getting around it for Golden State. This game was given away by an inability to contain the ball and rotate with speed and precision defensively, not to mention major struggles creating good shots and taking care of the ball against a defense switching across all five positions.

The Warriors entered Sunday's action with a -3.6 net rating in the clutch, 17th in the league, per NBA.com/stats. Even that underwhelming level of play would have been enough to beat the Nets. Instead, Golden State looked inept on both ends versus a Brooklyn team that had lost four of five since Kevin Durant went down with injury.

Yikes.

Jonathan Kuminga, pressuring the rim

No team in the league takes fewer shots at the rim than the Warriors. They've never ranked highly in that area under Steve Kerr, even when Durant was balling in the Bay, and won't as long as the offense still revolves around the singular threat presented by Steph Curry.

But just because that lack of persistent rim pressure hasn't doomed Golden State hardly means this team couldn't use more of it, one of the many reasons why Kuminga's improvement this season looms so large. No player on the roster boasts his blend of size, explosiveness and finishing prowess, and it's not really close unless Wiggins is locked in and playing aggressive.

Kuminga had three straight scores at the rim early in the second quarter: An impressive one-dribble bump and finish from the dunker spot right through the chest of Defensive Player of the Year candidate Nic Claxton; a soaring layup on the roll down the middle of Brooklyn's defense; and this transition dunk courtesy of Jordan Poole's wild hook outlet pass.

What did Golden State do a few minutes later? Go right back to exploiting Kuminga's physical gifts with an early-clock post isolation on Irving.

His finishing package isn't all power and pop, either.

Check out Kuminga's footwork and touch—with his left hand!—on this key transition score as the Warriors responded to Brooklyn's third-quarter run.

The 20-year-old's still-developing shooting stroke isn't as big an issue when he confidently rumbles into space like this.

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Kuminga, in just his second game back after missing three weeks due to foot soreness, is clearly still finding the right balance between pointedly seeking his own offense and finding it through the team construct. He took a couple ill-advised jumpers on Sunday, and picked up an offensive foul trying to plow through Ben Simmons on the block after he'd already been stonewalled.

But the more Kuminga functions in his new role as a two-way bench sparkplug, the more comfortable he'll get scrounging for buckets at the rim through split cuts, pick-and-rolls, filling the lane in transition and attacking short close-outs. Making him even more valuable to Golden State? Kuminga sometimes held his own checking Irving, the only Warrior other than Wiggins on Sunday night who had a chance of keeping the Nets superstar in check.

Toothless starting lineup defense

The first possession of this game, unfortunately, proved a harbinger for the defensive performance of Golden State's new starting lineup pretty much from start to finish.

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The Nets kept getting whatever they wanted offensively early. Irving roasted switches, quick ball movement produced open threes and the Nets got an uncontested layup off a make after the Warriors failed to find bodies in transition, prompting a quick timeout from Kerr.

Kerr had seen enough from his team's updated opening five when Irving grabbed his own miss twice right between a flat-footed Thompson and Poole. Looney entered for Poole at the next dead ball.

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Irving continued targeting Thompson and Poole—plus Steph Curry late—throughout this game.

The Warriors tried hiding Poole on Ben Simmons, fully aware of the physical and mental hurdles that have prevented the former All-NBA honoree from being a real scoring threat with the Nets. Simmons' offensive limitations aren't as big a factor when he's playmaking, though, especially when setting up a player like Irving.

https://streamable.com/740fck

 

The defensive weaknesses of Golden State's new starting five were laid bare by Irving and the short-handed Nets.

Wiggins is the only one approaching a perimeter defense ace in that lineup. Klay has clearly lost a step laterally. Curry mostly fights like hell, but remains a target for elite ball handlers. Poole is prey. The very theory of this group's defensive effectiveness falls apart without Green on the back line.

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The Warriors' starters didn't give this game away. Kerr stashed Wiggins, still re-acclimating to the speed and physicality of the game over two weeks since returning from injury, on the bench for crunch-time, alternating between Kuminga, Draymond and Looney up front. Poole left for a brief stint on either side of the one-minute mark, but was otherwise on the floor late alongside Curry and Thompson.

It's not just that trio's lack of collective size and athleticism that can make it so problematic defensively. Curry, Thompson and Poole simply aren't defense-first players, either, absent the tools and mindset to regularly string together stops against quality competition when it matters most.

Pay close attention to the defensive performance of Golden State's updated starting unit and quintets featuring the Warriors' three flame-throwing guards from here on out. There's a reason Kerr mothballed the Poole Party lineup during last season's playoffs. If Golden State couldn't win a title in 2022 relying on that group, why could it a year later?