Originally published on ProWrestlingSheet.

Lucha Underground referee Rick Knox broke his collarbone at a recent season four taping and will likely be unable to officiate for months after undergoing surgery.

Sources tell us Knox broke his left clavicle in three pieces following a spot gone wrong at the LU taping, but it's unclear exactly how the injury occurred.

Rick posted a photo on social media of the gnarly scar after surgery and recently tweeted saying his surgeon "marked out" because he's a Lucha Underground fan.

Check out picture below.