Rollins and Riddle have shared a heated rivalry that will see the pair clash in a ‘Fight Pit’ match at WWE’s Extreme Rules event this Saturday (8 October).
And Cormier, one of just four dual-weight champions in UFC history, will make his first WWE appearance as he officiates the contest between his fellow Americans.
Upon the announcement of his involvement at Extreme Rules, the ex-heavyweight and light heavyweight champion wrote on Instagram: “I will be fair. I’ll be honest. I’ll be impartial. And I will not take anyone’s s***.
“I will be there for a reason. The law has been called in, and I will enforce it with every part of myself to the fullest extent.”
Riddle previously competed in the UFC between 2008 and 2013, fighting at welterweight and compiling a 7-3 record – while also seeing two bouts end as No Contests.
Meanwhile, Cormier, 43, retired from mixed martial arts in August 2020 after suffering a second straight loss to Stipe Miocic.
Prior to those defeats, Cormier knocked out Miocic to win the UFC heavyweight title and become just the fourth ever UFC fighter to hold two titles at once – following in the footsteps of Conor McGregor, Amanda Nunes and Henry Cejudo.
“DC” reigned as light heavyweight champion at the time that he added the heavyweight title to his collection, though he later relinquished the light heavyweight belt. The former Olympic wrestler then lost the heavyweight gold to Miocic in the pair’s rematch and failed to regain it in their trilogy bout – the final fight of Cormier’s pro MMA career.