The super middleweight fight between Mexican countrymen Julio Cesar Chavez Jr. and Alfredo Angulo, scheduled to take place Saturday at Staples Center in Los Angeles, was canceled Monday, Premier Boxing Champions announced.

The scheduled 10-round fight was scheduled to air on Showtime as part of a telecast of preliminary bouts before the start of the Showtime PPV card (9 p.m. ET) headlined by the fight between heavyweight world titlist Deontay Wilder and lineal champion Tyson Fury.

According to the PBC announcement, Chavez Jr., a former middleweight world titlist, was pulled out of the fight because his father, legendary Hall of Famer Julio Cesar Chavez Sr., and his team "didn't believe Chavez Jr. was ready to return to the ring. Chavez, Jr. will return at some time in the future. Angulo will still appear in a bout on the undercard."

There has been chatter for days that Chavez would pull out of the fight because he had not completed required medical exams to get a license to box in California. He also had a recent stint in rehabilitation to deal with a substance abuse problem.

Chavez (50-3-1, 32 KOs), 32, who is just 4-3 in his past seven fights dating to 2012, has not been in the ring since giving virtually no effort in a shutout loss to Mexican rival Canelo Alvarez in their heavily hyped showdown on May 6, 2017, in Las Vegas.

Long-faded brawler Angulo (24-7, 20 KOs), 36, who was at his best as a junior middleweight, is 2-5 in his past seven fights since 2013 and is coming off an eight-round split decision loss to former junior middleweight titlist Sergio Mora in April 7.

Showtime's pre-pay-per-view telecast, initially slated to begin at 6:45 p.m. ET, will instead begin at 7:45 p.m. ET and has been cut to a one-fight show featuring the originally scheduled mandatory fight between light heavyweight world champion Adonis Stevenson and interim titlist Oleksandr Gvozdyk from the Videotron Centre in Quebec City. The fight will also stream live and for free on the Showtime Sports Facebook and YouTube pages.

PBC also announced that junior middleweight contender Julian "J Rock'' Williams (25-1-1, 15 KOs), 28, of Philadelphia, has been added to Saturday's undercard in Los Angeles, where he will take on Javier Francisco Castro (28-8, 23 KOs), 34, of Mexico, in a 10-round bout.

Williams has won three fights in a row since suffering a fifth-round knockout challenging Jermall Charlo for his world title in December 2016. Castro is 1-4 in his past five fights, with the lone win coming against an 8-22 opponent in his last fight in May.