Carl Frampton will fight Everth Briceno in his IBF inter-continental title defence at Wembley on 20 July.
The Belfast super-bantamweight, 26, was originally due to face Fabian Orozco, who is unable to fight for 30 days after being knocked out last week.
Nicaraguan Briceno has won 35 of his 45 contests, with 26 stoppages.
The 35-year-old has challenged for the WBO super-flyweight title twice and secured back-to-back wins over Elvis Guillen in his last two fights.
Briceno took Leo Santa Cruz, a possible future opponent of Frampton, to 11 rounds in 2011 before being stopped.
"Everth Briceno is a great fighter - the guy has fought for the world title on two separate occasions," Frampton told Sky Sports.
"I am in the best shape of my life right now. I am improving in training every day, sparring great, and I'm looking forward to showcasing my skills at Wembley."
Orozco is unable to fight Frampton, who is unbeaten in 16 contests, after being stopped by Julian Aristule in an IBF latino title bout.
Frampton's last outing was a win over Kiko Martinez at the Odyssey Arena in February.
The July date is set to be his first appearance with promoter Frank Warren after parting from Eddie Hearn's Matchroom firm.
Frampton has signed a four-fight deal on the BoxNation channel, starting with the London contest next month, and hopes to contest a world title by the third fight.