Usually the Dodgers wait until October to collapse.

This season, they’re getting a head start.

Usually the Dodgers wait until their first postseason opponent actually shows up before they wreck a summer’s worth of overblown expectations.

This season, their first postseason opponent is themselves, and the cratering begins now.

Tyler Glasnow is done, and it feels like the Dodgers could be done with him.

Their ace with a history of injuries is broken again, and a team with a history of autumn wounds could be breaking apart with him.

Either that, or the Dodgers are going to become the first team in baseball history to win the World Series with a one-man rotation.

Not gonna lie, folks, it’s not looking good, not after Glasnow lived down to every expectation Saturday afternoon by being eliminated from the postseason because of an elbow injury. This leaves a healthy and proven rotation of Jack Flaherty and … and that’s it.

Incidentally, that last paragraph was written before Flaherty gave up four runs in three innings against the playoff-hungry Atlanta Braves later Saturday in easily his worst start since joining the Dodgers at the trade deadline.

Is it any wonder that manager Dave Roberts responded to the Glasnow news by telling reporters, “It’s certainly a hit.”

As hard as any Shohei Ohtani blast, for sure.

Yoshinobu Yamamoto is now the No. 2 starter behind Flaherty, and yet he’s thrown only four innings in the last three months, and he’s never pitched in a major-league postseason, and how can anybody really trust him?

Walker Buehler might be the third starter, and he’s 1-5 with a 5.95 ERA. Clayton Kershaw could be fourth starter, but he’s suffering from a severe toe injury sustained while rehabbing from shoulder surgery and … trust us, the aging warrior is a mess.

Dodgers pitcher Bobby Miller talks to pitching coach Mark Prior after struggling against the Angels on Sept. 4.

(Wally Skalij / Los Angeles Times)

Bobby Miller would be included in this rotation except, well, he’s been one of the majors’ worst pitchers this season. Then there’s Landon Knack, a rookie who has had only 10 starts and never has experienced anything close to a playoff duel.

It’s officially bad, and there’s little hope it can be better, and raise your hand if you think the Dodgers could slow down a veteran Philadelphia Phillies lineup in a championship series battle.

Hands down, the answer right now seems to be no.

Certainly, the Dodgers have an awesome lineup of their own, capable of scoring at least five runs a night even in a pressurized October setting.

But the ancient adage remains forever true — pitching wins championships. And with the loss of Glasnow, the Dodgers just don’t seem to have enough starting pitching, and if you insist on knowing what that looks like, check out recent playoff debacles against San Diego and Arizona for a quick reminder.

“I’m still confident,” Roberts told reporters in Atlanta on Saturday. “I don’t think there’s one way to win a championship. I think you can look back at the teams recently and how their staffs came together and who stepped up for each team’s staff. So we’re going to have the guys we have, and I feel confident in whoever we run out there.”

That confidence wanes a tad when one realizes that no team in the last decade has won a pennant without at least two six-inning starts in the division and league championship series combined. Flaherty and Yamamoto have three six-inning postseason starts in their careers combined.

So, yeah, the creative Dodgers braintrust can piece the pitching together. But they still need the cornerstone pieces to show up big, and perhaps the most important piece just disappeared.

The Dodgers bet big last winter — $136.5 million big — that Glasnow would overcome his well-known injury bug and become the ace the Dodgers have been missing in recent postseasons. For 22 starts this summer, he made good on that bet, going 9-6 with a 3.49 ERA and a career best in innings pitched and strikeouts.

But he is what he is. There’s a reason he’s never made more than 22 starts in a season. There’s a reason that, at age 31, he keeps breaking down virtually every season.

He’s brittle. That’s it. That’s him. Seemingly everybody in baseball understood this. Why didn’t the Dodgers?

Dodgers pitcher Tyler Glasnow reacts after giving up a home run to the San Francisco Giants on July 24.

(Gina Ferazzi / Los Angeles Times)

In making one of the worst investments of his storied executive career, Andrew Friedman thought his renowned reclamation experts could turn Glasnow into something that didn’t always resemble “glass, now.” These experts have done wonderful revivals with many lost players. But they’re not miracle workers. Hopefully, they know that now. Hopefully, they realize that once again, they were burned by thinking they’re the smartest folks in the room.

“Tyler Glasnow is a guy that we feel like the arrow is really pointing up and that, over the next few years, he is really going to take on a lot of starts,” Friedman told reporters this spring. “The work ethic is there. We spent a lot of time digging into that. And that’s a bet we’re making.”

The digging wasn’t deep enough. The bet was badly lost. And now another seeming Dodgers dream season could be derailed because of it.

Yeah, this one is on Friedman. But before piling on, remember he’s the same guy who brought in the hitters that have shaped a top-of-the-order lineup unlike perhaps any in baseball history.

From Ohtani to Mookie Betts to Freddie Freeman to Teoscar Hernández, that’s Friedman, give him credit for that.

Problem is, for the third consecutive season, this sort of firepower could be rendered irrelevant because Friedman’s Dodgers just can’t seem to figure out the pitching.

So far, Glasnow has been a ghastly mistake.

The annual haunting begins now.