ESPN’s most esteemed boxing reporter had his credential rejected for the most significant fight of the year.

The Post has learned that Showtime and Al Haymon’s PBC blocked Mike Coppinger from covering Saturday night’s blockbuster fight between Errol Spence Jr. and Terence Crawford in Las Vegas.

The reasoning for blocking the credential was not immediately clear.

Coppinger declined to comment for this story.

The Post has reached out to ESPN, Showtime and PBC for comment.

This is not the first time there has been a controversy involving an ESPN talent and boxing credentialing.

In 2015, then-ESPN host Michelle Beadle and then-CNN host Rachel Nichols did not receive credentials for a Floyd Mayweather fight (though Beadle was apparently credentialed after she’d already headed home).