Jeurys Familia of the New York Mets stands on the...

Jeurys Familia of the New York Mets stands on the mound after surrendering a ninth-inning, three-run double against the San Francisco Giants at Citi Field on Wednesday, May 10, 2017. Credit: Jim McIsaac

We figured the history lesson could wait. Despite the Mets’ dizzying epidemic of injuries — from Steven Matz and Seth Lugo, to Lucas Duda and Travis d’Arnaud, to Yoenis Cespedes and Noah Syndergaard, to whatever the heck is wrong with Matt Harvey — the eternal optimists still could cling to baseball’s favorite mantra: It’s early.

Then Jeurys Familia happened Thursday. Seemingly out of nowhere, the Mets announced that Familia had been diagnosed with an arterial clot in his right shoulder and would be traveling to St. Louis to visit Dr. Robert Thompson, who specializes in thoracic outlet syndrome and did the repair on Harvey a year ago.

The surgery ended Harvey’s season on July 4. Now Familia is headed down a similar path. And just like that, it’s 2009 all over again, the cursed year the Mets put 19 players on the disabled list, including eight former All-Stars, and plummeted from contention at breathtaking speed.

For those who don’t remember, the Mets spent $149 million on their 2009 roster after late-season collapses the previous two years. On May 13, or 33 games into the ’09 season — right where these Mets are now — that group was 18-14 and in first place, with a one-game lead over the Phillies. The last day the Mets were atop the NL East was May 29. In the free-fall that ensued, they went 43-73.

The moral of the story? Eventually, too many injuries become too much. Every team has its breaking point. The ’09 club lost Carlos Beltran, Carlos Delgado, Jose Reyes, John Maine and J.J. Putz all before the end of June, just to name a few. As bad as that epic fail was, there is an argument to be made that what the current Mets are experiencing is actually worse

Five weeks into the season, Sandy Alderson’s rotation is so thin that he’s already been forced to use two starting pitchers who weren’t even on his radar screen in March: Adam Wilk and Tommy Milone. The GM has a third in Harvey, whose heavily damaged reputation will be on the line when he takes the mound Friday night in Milwaukee.

Matz, who in the Mets’ estimation is physically sound, has yet to throw a competitive pitch. Lugo is working his way back while keeping his fingers crossed that his torn UCL — now manageable — doesn’t completely snap.

In the meantime, whatever prognosis we’ve been told on Syndergaard’s status (torn lat muscle) really doesn’t matter a whole lot. The Mets, in this rapid deterioration, may need binoculars to see the top of the division before Thor even picks up a baseball in another five weeks. And there’s no point in counting on Cespedes as a savior just yet.

A few days ago, Terry Collins casually dropped two weeks as a potential return neighborhood for Cespedes from his hamstring condition (strain, sprain, cramp?) even though the Mets, by their own admission, still are trying to figure out how to combat his chronic leg problems. At $110 million, Cespedes is being paid big money to be the engine of this offense, but he has to stay on the field to do so.

And therein lies the Mets’ most vexing issue — again. Keeping their players upright and functioning. If that doesn’t happen, the Mets still might be able to hang around in the wild-card hunt with some of the pieces they’re running out there, along with maybe a boost from the eventual call-up of top prospect Amed Rosario. If the Mets don’t rebound, or get healthier, as the trade deadline approaches, they’ll be better off as sellers, given the 10 free agents on their roster.

Because the cracks are showing. Familia said he was fine and his arm “felt great” after Wednesday’s blown save, but he certainly didn’t look like it as he struggled terribly with the command of his pitches. There was no mention from Familia — or anyone else on the Mets — that he was dealing with symptoms that could be related to the discovered clot, such as numbness in his fingers or the arm itself.

That came Thursday, when the Mets added their closer to a disabled list that included three starting pitchers (with the ace), the cleanup hitter, the catcher and the captain-in-limbo. At this rate, the next step for the 2017 Mets will be the autopsy.