SAN ANTONIO – Sebastian Contursi considers mandatory title defenses to be the probable obstacle that’ll prevent an immediate rematch between Brian Castano and Jermell Charlo.

Both 154-pound champions expressed interest in a second fight following their controversial 12-round split draw at AT&T Center, but Castano’s manager reminded reporters during their post-fight press conference why an immediate rematch might be unrealistic. Contursi isn’t sure if Australia’s Tim Tszyu (19-0, 15 KOs), the WBO’s number one contender in the 154-pound division, has been declared the mandatory challenger for the junior middleweight title owned by Castano (17-0-2, 12 KOs).

Charlo, however, has at least two mandatory defenses due – one for the IBF (Bakhram Murtazaliev) and another for the WBC (Erickson Lubin). Russia’s Murtazaliev (19-0, 14 KOs) became the IBF’s mandatory challenger in November 2019, but he has won back-to-back bouts on Charlo’s past two undercards and expects to challenge Charlo next.

Houston’s Charlo (34-1-1, 18 KOs) isn’t interested in boxing Lubin again because he knocked out Orlando’s Lubin (24-1, 17 KOs) with one punch in the first round of their October 2017 fight at Barclays Center in Brooklyn. Lubin has won six straight fights since Charlo knocked him out to become the WBC’s mandatory challenger for Charlo’s crown again.

Uzbekistan’s Israil Madrimov (7-0, 5 KOs) is the WBA’s number one contender for Charlo’s super welterweight title.

There was not a rematch clause in the contracts for the full title unification bout between Charlo and Castano in part because they’ll have mandatory obligations to the four governing organizations that sanction their titles.

“As a manager, obviously I cannot disclose certain confidential things that are included in any contract, actually,” Contursi said. “But I agree with Brian in this regard, that if both boxers wanna do it, they both belong to [Premier Boxing Champions]. … I think if both champions really wanna do it, the obstacle might be the sanctioning bodies’ mandatories. I’m not blaming them. They have their own rules. This was a very unique opportunity.

“If they can work out, among them, and they can work out the mandatories, whatever they are. Because we don’t even know if we have a mandatory [due for] the WBO – we were so focused on this unification [fight]. But needless to say, you guys know that we would prefer unification like this, and not any crappy mandatory here and there. That’s from my perspective. But it’s not like it’s a guaranteed rematch because of these things. You cannot guarantee a rematch because there’s four sanctioning bodies, with four different mandatories involved.”

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