Rios v Gamboa cancelled
Brandon Rios and Yuriorkis Gamboa will not fight for the vacant WBA lightweight title on April 14.
Telecasters HBO have dropped the bout between the undefeated former champions from their schedule.
The bout would have taken place in Las Vegas, Nevada.
Gamboa, who won an Olympic Games gold medal for Cuba in Athens in 2004 before defecting to the United States, has a record of 21-0 with 16 knockouts.
Rios stands at 29-0, with one draw and 22 knockouts.
Gamboa, who skipped news conferences last week aimed at promoting the bout, would have jumped two weight classes to fight for the title.
He gave up his WBA and IBF featherweight titles a year ago for missing a weigh-in before stopping Mexico's Jorge Solis.
Rios vacated the WBA lightweight title by failing to make weight for a fight last November against Britain's John Murray, whom he stopped in the 11th round.
The lone blemish on Rios's record was a 2008 draw with US compatriot Manuel Perez. Since then, Rios has won 11 fights in a row, 10 by knockout and the other by disqualification.