UFC legend Rashad Evans will be in the ring next month ... not to fight, but to serve as referee in the celebrity boxing match between Blac Chyna and Alysia Magen.
The mixed martial artist -- who was inducted into the UFC Hall of Fame in 2019 -- made the IG announcement on Tuesday with a clip of Chyna and Magen's first face-off ... where things got a little heated.
"I'll be ref' at this event," RE said with a bunch of fire emojis.