Chael Sonnen on Monday said the meeting between former UFC women’s bantamweight champ Miesha Tate and Jessica Eye was not the originally planned matchup for next month’s Submission Underground 2.

Sonnen claimed jiu-jitsu champion Mackenzie Dern turned down an offer to meet Tate at the FloGrappling.com-streamed event, accusing her of being “scared” to face the UFC vet on Dec. 11 at Roseland Theater in Portland, Ore.

“Mackenzie Dern is supposedly a world champion in jiu-jitsu,” the Bellator light heavyweight and grappling promoter complained to MMAjunkie Radio. “Miesha Tate accepted on the spot, coming in to McKenzie’s world, (and Mackenzie is) trying to break into MMA. So it’s the opportunity of a lifetime, because she is now going to get to go against the queen of MMA who just was the world champion a minute ago – in her realm, which is jiu-jitsu.

“Miesha accepts to come into her world, Mackenzie turns the match down. This is insane. This is insane that you were scared to compete in (the sport) which you were allegedly the champion of the world.”

Dern’s manager denied turning down Tate specifically. He said the decision not to accept the match was based on a previous choice to focus on her MMA training for the remainder of the year rather than compete again.

“She wasn’t competing in December regardless,” Daniel Rubenstein told MMAjunkie. “She also turned down a fight that didn’t make sense to us. She was planning to fight for Legacy (FC) in December, and then take the rest of December off. She was focused on fighting, and when the fight did not materialize, she basically said she’s going to continue to train and get better for MMA.”

Dern, who won the 2015 Abu Dhabi Submission Wrestling World Championship at 60kg, made her professional MMA debut in July and won a decision. This past month, she submitted Montana Stewart at Legacy FC 61.

Dern’s inclusion would undoubtedly have been a win for Submission Underground. But with the grappling champ out of the picture, Sonnen and his team selected UFC vet Eye, who recently said she’d take a year off to recover from a 1-5 slump in the octagon. The two have circled each other on the professional MMA circuit, with Tate winning a unanimous decision over Eye this past year at UFC on FOX 16, but never competed against each other in grappling.

Now complicating matters is the status of Tate. At this past Saturday’s UFC 205, she retired from the sport after getting outpointed by Raquel Pennington on the pay-per-view main card of the promotion’s banner event at Madison Square Garden. Sonnen said he wasn’t sure whether that decision would apply to next month’s grappling event. Tate’s rep, Josh Jones, told MMAjunkie the former champ hasn’t made a decision yet.

Check out the video above to hear Sonnen discuss the upcoming event.

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