The Mets don’t have any plans to demote struggling Edwin Diaz to the minors, or even relegate him to an ever lower-leverage role.

But it sure sounds as if they would if they could.

“At this point, the way we’re set up, we really can’t afford to do that,” Mickey Callaway said as the Mets prepared for a huge three-game set at NL East-leading Atlanta beginning Tuesday. “He’s going to continue to get big outs for us, continue to pitch in big games. And like we did [Saturday night when Seth Lugo pitched the final two innings and Diaz remained in the pen], we’ll pick our spots and do the best we can to win a game every single night.”

Diaz was supposed to be the solution, not the problem. Baseball’s best closer a year ago with 57 saves — tied for the second-most all-time — has been mired in a slump. And it’s only getting worse, with him pitching to a bloated 7.62 ERA over 13 innings since the start of July.

With Lugo limited by a partial tear in his elbow ligament, the Mets are limited in how often they can use him, and Callaway admitted that “it’s difficult, not knowing if he’s going to be available the next day.”

But Callaway acknowledged he’d start giving Lugo higher-leverage looks.