Claressa Shields will find it 'very hard' to conquer MMA, despite her debut win last week, as it takes 'years' to learn the correct skills, says Bellator boss Scott Coker.
The 26-year-old American, who is one of the biggest stars in women's boxing, made a successful switch to MMA last week as she stopped Brittney Elkin in her first bout in the Professional Fighters League.
But Coker, president of one of the biggest MMA promotions, has questioned whether Shields can replicate her boxing success in a different combat code.
"Congratulations to her," said Coker. "She's an Olympic medallist and she's had a great world championship career in boxing.
"I just will say this. I think the road gets much tougher moving forward, and somebody that really has a good wrestling background and a good submission game is going to be very dangerous against a pure striker.
"It's going to take her years to really learn the submission game and the wrestling to fight somebody that has a wrestling pedigree. It's going to be very tough.
"To me, she'll always have a shot, because she has such great striking hands, but as far as moving forward, I think as opponents get tougher, she's going to have her hands full."
Shields was forced to the ground by Elkin for two rounds before delivering an explosive finish in the third as a barrage of punches prompted referee Gasper Oliver to wave it off.
"I never doubted myself winning a boxing match in my life," Shields told ESPN. "MMA, it's like it's possible I can lose this first fight.
"I just had a never-quit attitude every round.
"She had me on the ground, but she couldn't hurt me. Her punches didn't hurt me. She tried to get me in an armbar and that didn't hurt me.
"I may have lost these two rounds, but I'm not losing this fight."