The New York Yankees have entered September staring at a brutal gauntlet of contenders. But instead of focusing on player performance, the majority of the heat is now directed at manager Aaron Boone. One MLB insider has brutally exposed what he sees as Boone’s fatal flaw—an unaddressed weakness that has been dogging the franchise throughout his reign.

On a recent episode of the Pinstripe Post podcast, veteran insider Joel Sherman didn’t hold back. He blasted Boone and the Yankees, accusing them of collapsing whenever they’re actually tested—citing a playoff record that defies any attempt at justification.

“The Yankees like to talk about being tough-minded,” Sherman said. “I’d like to see an iota of proof that they are. In the Aaron Judge era, whenever they face a team as talented or better, they fall apart.”

Sherman didn’t mince words about the damning facts. Since 2017, New York has been undefeated in playoff series against AL Central opponents, boasting a 7-0 record. But against real threats—the Astros, Red Sox, Rays, and Dodgers—they are winless: 0-7 in series, with an abysmal 10-25 game record.

“You can paint it a million ways, but the record speaks for itself,” Sherman added. “They could come out of these next 12 games atop the AL East, or they could go 2-10 and be fighting off the Rangers and Royals for a Wild Card spot. Boone says it’s all about doing, not talking. But in 2025, they haven’t done it against good teams. That’s the story of his entire tenure. Don’t tell me. Show me.”

Sherman’s condemnation comes as the Yankees face a make-or-break gauntlet. Their September schedule features relentless showdowns with playoff threats, including the Astros, Blue Jays, Tigers, and Red Sox. New York has already been thoroughly outclassed by Boston (2-8) and Toronto (3-7), providing more ammunition to critics who question whether Boone can handle real pressure.

The Yankees remain all but guaranteed a playoff berth, with FanGraphs putting their chances at 99.6%. But their World Series probability languishes at 12.0%, far behind the Dodgers’ 17.4%—numbers that reinforce the narrative: the Yankees rack up empty regular-season wins, then collapse when challenged.

Boone, who’s missed the playoffs just once since taking over in 2018, is nonetheless defined by a championship drought stretching back to 2009. Supporters may tout stability, but critics—especially in New York—see only mediocrity dressed up as consistency.

Sherman left no doubt where he stands. In his eyes, Boone’s Yankees lack both tactical depth and mental toughness when it counts most. Now, as the hardest stretch looms, Boone’s credibility looks more fragile than ever.

The Yankees are running out of chances to silence their critics. If Sherman’s brutal assessment is accurate, another underwhelming finish won’t just sting; it will serve as undeniable proof that Boone can’t rewrite the franchise’s narrative.