IBF, WBC, WBA middleweight champion Claressa Shields believes her division rival, WBO champion Savannah Marshall, is trying to buy "extra time" to prepare for a planned undisputed world title clash.

Promoter Ben Shalom of BOXXER had planned to stage the contest on a date in July, but the fight was pushed back after Marshall underwent a minor surgical procedure and indicate that she needed additional time to recover.

In a recent interview, Marshall said her doctors have supplied details of the surgery to Shields' handlers.

Shields does not feel the procedure is as severe as Marshal is making it out to be.

If the fight does not take place by September 3, then Shields will head in another direction.

"It's all mind games and it's extra time," Shields told Sky Sports News. "Her and her trainer have realized that it is not what they thought it was going to be.

"I'm not going to let Savannah steamroll me, she's not going to knock me out. She's going to have to be in great shape, she's going to have to be mentally tough and she's going to have to endure a lot of hard punches, body shots, head shots and I don't think she's ready for that right now.

"If it doesn't happen [by] September 3, Savannah Marshall is going to have to find somebody else to play with. That's it. The fact that I've allowed it to be pushed back to September, she has enough time to heal and get ready from whatever her injury is, and we can get the fight on. She says he's going to knock me out in two rounds, so it shouldn't take too long."