Cherneka Johnson has the chance to become undisputed world champion after the Australian boxer was called in to replace Denmark's Dina Thorslund, who has announced her pregnancy.

Already the WBA bantamweight world champion, Johnson will have the biggest fight of her career, stepping into the ring on July 11 (local time) at Madison Square Garden to take on the IBF champion, American Shurretta Metcalf.

Because of her pregnancy, Thorslund voluntarily relinquished her WBO belt, while the WBC approved her title as Champion in Recess.

A victory would make 30-year-old Johnson Australia's first undisputed world champion in the four-belt era after George Kambosos fell short in his quest to pull off the feat against Devin Haney in 2022.

The 10-round showdown with Metcalf (14-4-1, 2 KOs) is on the first-ever all-women's professional boxing card at the famous New York venue.

It's headlined by the third battle between Ireland's Katie Taylor and Amanda Serrano of Puerto Rico.

Signing with an American promoter, it is the first fight in the US for Johnson (17-2, 7 KOs).

"It's a dream come true to fight at Madison Square Garden," said Johnson, who is New Zealand-born but lives on the Gold Coast and fights under the Australian flag.

"This feels like a true 'pinch me' moment.

"Not only will I be defending my title, but I'll also become the undisputed champion ... the magnitude of this moment isn't lost on me, and I'm ready to rise to it."

Meanwhile, Andrew Moloney's comeback fight has been locked in less than a year after he announced his retirement following a controversial loss.

Australia's former super flyweight world champion was ordered to fight Mexico's Argi Cortes in an IBF eliminator, with the pair squaring off in Monterrey, Mexico, on July 19 (local time).

The winner will become the mandatory challenger to Willibaldo Garcia, who edged fellow Mexican Rene Calixto to claim the vacant IBF crown.

The chance comes less than a year after 34-year-old Moloney quit the sport in a rage after losing on points to Pedro Guevara for the interim WBC super flyweight title.