Carl Frampton has relinquished his IBF World super-bantamweight title ahead of his WBA Super World featherweight title showdown in New York.
In order for Frampton to take on Santa Cruz this summer, the Belfast boxer had to hand back his IBF crown as he would not have been able to fulfil the federation's obligations for a title defence.
The Santa Cruz fight at featherweight - a step up in weight divisions - was the more lucrative option for the Jackal.
The 29-year-old undefeated Belfast man wanted to make clear his gratitude to the International Boxing Federation (IBF) ahead of his world featherweight title challenge.
He said: “I’m delighted to be fighting Leo Santa Cruz for the world featherweight title but I would like to say a huge thank you to the IBF for their professionalism during my time as their super bantamweight champion.
“I have been a proud IBF world champion for nearly two years and I one day hope to once again become an IBF champion. I wish Shingo Wake (the IBF’s mandatory challenger at super bantamweight) the very best in his championship fight.”
The clash with Leo Santa Cruz will be Frampton's first bout since defeating Scott Quigg on February 27 in Manchester to become the WBA and IBF Unified champion
Earlier this month, Frampton was stripped of his WBA super-bantamweight title.
The title was taken away from the Tiger's Bay man after he did not fight Cuban Guillermo Rigondeaux.
Victory would see the Belfast boxer become the first Northern Ireland fighter to win world titles at two weights following his success in the super-bantamweight division.