Claressa Shields has accused her rival Savannah Marshall of "faking an arm injury".The eagerly-anticipated fight between the two boxers has been pushed back to September after Marshall had a “small operation".Marshall’s promoter Ben Shalom has been keen to stress that the fight against Shields will happen, but the American star has now accused her opponent of faking her injury.In a series of bizarre posts on Twitter, Shields asked why Marshall was not wearing a cast following her operation. “Y’all talking bout Marshmallow had surgery on her arm… where tf is the arm sleeve, the cast, SOMETHING! This bum faking an arm injury! It don’t even matter! I’m F’ing her up! All y’all Marshall fans gonna be silent! Forever! #GWOAT 🔪”Shields then shared a video of Marshall at The Cube Live Experience in Manchester, asking again for evidence of her injury.“Look at this! @Savmarshall1 which arm you had surgery on!? Please do tell 🎤………. EXACTLY! Stfu! Not even an arm sleeve! Born a day not yesterday! Faking a damn injury! ‘see you in September! Same results! I’m gonna win!’ Hating ass bum."

In her final post, Shields shared a photo of herself and Marshall from 2015, claiming yet again that her rival was faking an injury.

“Dec 12 2015,” she wrote. “When my wrist was broken ! Literally had a cast on & @Savmarshall1 said I was scared to sparr her 😂 I’m irritated this morning cause I know she faking!!!!!”

Shields, who currently holds the WBC, WBA and IBF middleweight titles, has previously accused Marshall of being “terrified” of the upcoming clash.

The 27-year-old has fought the WBO middleweight champion once before, losing to the British star at the Women’s World Boxing Championships in 2012. As a result, Marshall is the only competitor to beat Shields at any level in boxing so far.

Following the delay to their next fight, Shields threatened to give up on the encounter and return to MMA, but Shalom has urged her to be patient.

“Savannah had to have a small operation that unexpectedly required her to need a few weeks of recovery," he said.

“That meant, obviously, that July was too early, which means that we’ll just go back four or five weeks.

“Hopefully Claressa is going to be sensible and accept that both of them need to be fit and ready for what is the biggest fight in both of their careers and one of the biggest fights in the sport.”