LAS VEGAS – The most intriguing fight on the Canelo Alvarez-Dmitry Bivol undercard has been scrapped.

BoxingScene.com has learned that Filip Hrgovic has withdrawn from his 12-round heavyweight fight against Zhang Zhilei. Croatia’s Hrgovic (14-0, 12 KOs) and China’s Zhilei (23-0-1, 18 KOs) were scheduled to meet in an IBF elimination match Saturday night at T-Mobile Arena that would’ve determined the New Jersey-based sanctioning organization’s mandatory challenger for the winner of the upcoming rematch between champion Oleksandr Usyk and former champ Anthony Joshua.

Matchmakers for Eddie Hearn’s Matchroom Boxing, which promotes Hrgovic and Zhilei, were seeking a replacement for Hrgovic on Monday morning for what would be a 10-round fight for Zhilei on the Alvarez-Bivol undercard.

The IBF’s rules indicate that their elimination match must be rescheduled for a later date. Zhilei wants to fight Saturday night, though, so that he won’t have wasted an entire training camp.

Hrgovic’s father reportedly died early in April. His father’s death is believed to be the reason Hrgovic was unable to concentrate on training and ultimately withdrew from his fight with Zhilei.

The 29-year-old Hrgovic, who won a bronze medal at the 2016 Summer Olympics in Rio de Janeiro, is the IBF’s third-ranked contender in the heavyweight division. The 39-year-old Zhilei, a silver medalist at the 2008 Summer Olympics in Beijing, is ranked 13th by the IBF.

They’re supposed to box to become the IBF’s mandatory challenger because Zhilei and fifth-rated Frenchman Tony Yoka were the only two of the nine IBF-ranked heavyweights approached who were willing to enter negotiations with Hrgovic’s co-promoters, Eddie Hearn’s Matchroom Boxing and Wasserman Boxing, for this elimination match. Yoka (11-0, 9 KOs) ultimately committed to a fight with Scotland’s Martin Bakole (17-1, 13 KOs), which was rescheduled from January 15 to May 14 at Accor Arena in Paris.

Seven other heavyweights turned down the IBF’s invitation to negotiate for this title eliminator with Hrgovic’s handlers due to injuries, scheduling conflicts or other reasons. Matchroom and Wasserman then won an IBF purse bid February 24 with a joint offer of $650,000.

If their fight is rescheduled, the 6-foot-6 Hgrovic is entitled to 60 percent, or $390,000, of the winning bid because he is the higher-ranked contender. The 6-foot-6 Zhilei’s side would receive $260,000, or 40 percent of the winning bid.

The number one spot in the IBF’s heavyweight rankings is vacant. Cuba’s Luis Ortiz (33-2, 28 KOs, 2 NC) is ranked second by the IBF.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.