Edwin Diaz’s four-seam fastball this season is averaging 96.6 mph, a number that most pitchers would celebrate.

But Diaz isn’t most pitchers.

The Mets closer was averaging 99.1 mph with that same pitch in his historic 2022 season — before missing all of last year rehabbing from surgery to repair the torn patellar tendon in his right knee — and now Diaz and pitching coach Jeremy Hefner want to find that missing velocity.

In his last appearance, against the Pirates on Monday, the right-hander had a variance between 94.9 mph and 97.7 mph with the four-seamer. The low end of that spectrum is where the questions arise.