Terry Flanagan is to make the third defence of his WBO lightweight title against South Africa's Mzonke Fana on the undercard of Tyson Fury's July 9 rematch with Wladimir Klitschko.
Fana, 42, had been scheduled to fight Ghana's Emmanuel Tagoe on July 8 until he withdrew when offered the fight with 26-year-old Flanagan, who won the vacant title last July.
Fana has twice won the IBF super-featherweight title, last doing so in 2010.
"It doesn't get any bigger than fighting as chief support and right before the lineal heavyweight championship of the world," said Flanagan.
"(Fana's) highly experienced, tough and has a very good jab. He will be coming over here looking to take my title but it's not going to happen."
Fury is to defend his WBO and WBA heavyweight titles for the first time at the Manchester Arena.