Jeurys Familia delivered his most dominant performance this season on Sunday — a 13-pitch, three-strikeout eighth inning against the Nationals. Edwin Diaz followed in the ninth with more Edwin Diaz, circa 2019 — a walk, a homer and more Citi Field boos.

The Mets must keep sending both out in big spots and hope Familia has revived and Diaz could still find his 2018 form.

Because if not them, who?

And because this is the major leagues this season.

Mets fans should not suffer baseball myopia — short-man nearsightedness. As the Nationals emphasized over the weekend at Citi Field, the Mets are not alone when it comes to untrustworthy bullpens.

A variety of modern factors, notably pens being overstressed and the ball flying, have manifested in the worst collective pen ERA (4.58) since 2000 (think: a Steroid Era peak). Relievers are yielding a record 1.35 homers per nine innings. It is the rare team now that gets consistently strong pen work. The Yankees’ group has helped them rescue a rotation that struggles to provide quality innings. The Indians’ group has helped Cleveland overcome what was an 11 1/2-game AL Central deficit in early June.

The Mets, meanwhile, are like just about every NL contender — undermined by their pen. Even the clearly-league-best Dodgers have a mid-pack pen and a declining closer, Kenley Jansen, who provides their Achilles arm. Los Angeles tried to address it at the trade deadline by adding a pedigreed closer, but failed on, among others, Pittsburgh’s Felipe Vazquez and even Diaz.

The Dodgers’ interest should encourage Mets fans. Diaz and Familia are pedigreed relievers. There is ability with which to work, with which to upgrade, especially since August trades are now banned. At this point it is not about their whole season. If Diaz/Familia could pitch well the last quarter of a season, the Mets’ playoff chances soar. The Mets were one of seven non-Dodger National League squads over .500 to complete the weekend — all from the NL East or Central.

With apologies to the Reds, Diamondbacks and Giants, a look at how these other six contenders’ pens look with just under seven weeks left in the regular season:

Cardinals — The rare NL team in good relief shape, in part because what initially looked like a debacle, the Luke Voit trade to the Yankees, gave St. Louis Giovanny Gallegos, who has been among the majors’ best relievers. He had whiffed 37.3 percent of the hitters he had faced (third in the NL among relievers) to go with a 1.96 ERA.

John Brebbia, drafted by the Yankees in 2011 and released in 2013, has been terrific (2.95 ERA), as has John Gant (8-0, 2.80), whom the Mets traded to Atlanta in 2015 to get Kelly Johnson and Juan Uribe. Andrew Miller is not vintage, but since July 2, opponents were hitting just .174 against him. Converted starter Carlos Martinez has ably replaced closer Jordan Hicks (Tommy John surgery).

Braves — If they fail to hold onto a big NL East lead, the culprit probably will be the pen. Their second-half relief ERA is 6.90. Six of their next 12 games, beginning Tuesday at Citi Field, are against the Mets. Shane Greene, Chris Martin and Mark Melancon were added at the deadline, and in 15 combined outings were 0-2 with a 10.50 ERA, allowing 23 hits and 14 runs in 12 innings. Greene already had lost his closer’s role, and maybe Melancon has too, since Luke Jackson closed Sunday. Atlanta’s 6.90 second-half pen ERA was second-worst in the majors (for what it is worth, the Mets’ 3.46 is best from the NL East).

Nationals — Because of Washington’s rotation strength, its pen had thrown 17 1/3 fewer innings than any other team’s, yet the least-taxed pen of 2019 had a 6.00 ERA, 15th-worst in history, to go with a 16-28 record, indicative of how many games were being blown late. Plus, all this malfeasance has come with closer Sean Doolittle joining Seth Lugo as the best NL East relievers this season. New set-up acquisitions Daniel Hudson and Hunter Strickland have so far been good.

Phillies — Victor Arano, David Robertson and Tommy Hunter are out for the season, and the same may be true about Seranthony Dominguez and Adam Morgan, with Edubray Ramos sidelined until later this month at least. And it wasn’t like the first wave gave Philadelphia a strong pen. The Phils have tried to plug with relievers designated elsewhere (Mike Morin and Blake Parker), much as the Mets are doing with Brad Brach, not with much success.

see also The Cubs have another Craig Kimbrel problem to worry about The Cubs threw money at their bullpen problem and it...

Cubs — Craig Kimbrel has not been great, but had helped stabilize the back end. Now he is on the IL with a knee injury. This for a Cubs squad that has never had Brandon Morrow, has Steve Cishek now joining Brandon Kintzler on the IL, and endured implosions by Brach, Carl Edwards Jr. (since traded to San Diego) and Pedro Strop. Small pickups Derek Holland and David Phelps are helping, as is call-up Rowan WIck. The Cubs believe that the IL stints for Kimbrel and Kintzler should be brief.

Brewers — Milwaukee had arguably the NL’s best pen last year behind the trio of Josh Hader, Corey Knebel and Jeremy Jeffress. But Knebel (Tommy John surgery) has missed the whole season, and Jeffress has battled injury and ineffectiveness all season. No team has relied more on one reliever than the Brewers with Hader, whose five second-half homers allowed suggests the workload is wearing him out. Which is why the recent strong work of Matt Albers and Junior Guerra is so instrumental because an already ace-less rotation has its two best starters, Zach Davies and Brandon Woodruff, on the IL. The Brewers have the NL’s fewest starts of five and six innings.