We need to talk about Edwin Diaz

Superman has Kryptonite. Achilles had his heel. For New York Mets closer Edwin Diaz, the knee injury he suffered in the 2023 World Baseball Classic showed that not even he is invincible. Even the strongest among us have weaknesses.

It's been a long road for Diaz to get back to Citi Field. He missed the entire 2023 season with that knee injury, and the Mets missed him dearly, ultimately finishing the year in fourth place in the NL East, 12 games under .500, with the 22nd-best bullpen ERA.

Very few closers in modern baseball remain dominant for long. Mariano Rivera and Billy Wagner were rare exceptions to the rule, but for every Mo and Billy the Kid, there are countless examples of closers that seemed unhittable for a year or two or three but then fell off. Eric Gagne, Jonathan Papelbon, and Craig Kimbrel are just some examples of closers that were once thought to be the best in the game, but fell on hard times later in their careers.

I'm not ready to put Edwin Diaz in that category yet, but his results through the first month and a half of the season have been extremely concerning. Diaz blew a two-run lead to the Phillies last night, and when the Mets ultimately fell in extra innings, it marked a sharp 180-degree turn from the jubilation of a night ago when they came back to walk off the Braves on Brandon Nimmo's two-run homer in the ninth.

Edwin Diaz has lost his aura of invincibility.

There are few relievers that have ever enjoyed a season as good as Edwin Diaz in 2022. With an explosive fastball, an unhittable slider, and an entrance not matched since Rick Vaughn in Major League, every Diaz appearance felt like a sure thing. Now though, Mets fans begin biting their fingernails right as Timmy Trumpet's solo fades away in Narcos.

Last night's appearance against the NL East-leading Phillies was Diaz's second blown save of the season, just one less than he had in all of 2022. The solo home run he allowed to Bryson Stott to cut the deficit to one was the fourth long-ball he's surrendered this year, which is already one more than he had in all of 2022. And while it is true that he got squeezed by home plate umpire Gabe Morales on a clear strike to Whit Merrifield with the count 1-1, and then on an egregious check-swing call later in the at-bat to walk Merrifield and load the bases, the Mets can't blame the umpiring crew for last night's result.

Diaz is not the same guy that struck fear into the hearts of batters two years ago. His fastball is down an average of 1.7 mph according to Fangraphs, and batters are swinging and missing 14% less of the time on his slider than they did two years ago. Even more worrisome is how ineffective he's been pitching on back-to-back days.

Expecting someone to come back from a year off the mound and immediately resume being the most dominant pitcher in the game isn't really reasonable, but that knowledge provides no comfort as another winnable game slips away. It's still too early to say if this is who Diaz is now, or if he just needs more time to get back to peak form. What's clear, though, is the Mets, who are now 19-21 after last night's loss, need him to be the best closer in baseball again, or at least very close to it, if they hope to make a run to the postseason.