The Daniel Jacobs-Julio Cesar Chavez Jr undercard is interesting, to say the least. It has a world championship co-main event, two brits, a host of former world champions and a few amateur stars.

The main feature of the undercard will see Julio Cesar Martinez (14-1) facing off against Cristofer Rosales (29-4) in a clash for the recently vacated WBC world Flyweight crown. Martinez is actually coming off a fight for this exact championship, he seemingly had the belt won when he put down champ Charlie Edwards in August but, in a moment of madness, he struck Edwards whilst he was down and the fight was eventually ruled a no-contest after some confusion. Rosales is a former holder of this crown but dropped the belt in December of last year when he was outpointed by Charlie Edwards. The questions will be can Martinez keep his cool this time around? Or will Rosales recapture his crown?
Also, on the card, former WBO Super Lightweight champion Maurice Hooker (26-1-3) makes a step up to Welterweight when he squares off against unheralded Mexican Uriel Perez (19-4) in a ten rounder. On paper, this seems a routine win for Hooker, who is coming off a loss to Jose Ramirez which saw him lose his title, but Mexicans are known to be tough and not much is known about Perez other than this will be his best opponent that he has been in a ring with.

Amateur star Daniyar Yeleussinov (8-0) continues his rise up the paid ranks when he faces Alan Sanchez (20-4-1) in a ten-round welterweight contest. Yeleussinov has made a steady start to his pro career and will be looking to further that against the tough Sanchez who is coming off a loss to newly minted WBA welterweight champion Alexander Besputin.
One of the two live floats of the evening is a 6 round Featherweight contest between Raymond Ford who looks to advance his unbeaten record to 5-0 when he faces off against young Francisco Muro (3-6).
Sunderland’s Josh Kelly (9-0-1) looks to rebound after suffering the first blemish on his record last time out in June when he was taken to a draw against American Ray Robinson when he faces Winston Campos (31-6-6) in a ten-round welterweight contest. Campos has been fought a British fighter before when he was stopped by Josh Taylor back in 2018, he has also fought former lightweight title challenger Ismael Barroso where he lost by KO.

Another Brit is on the card in the form of former WBO Super Welterweight champion Liam Smith (28-2-1) when he takes on the challenge of tough Mexican Roberto Garcia (42-4) in a ten-round Middleweight fight. Smith is coming off of a TKO win, out in Garcia’s home country of Mexico, Mario Alberto Lozano and will hope a win here will propel him onto major fights again. The veteran Garcia is coming off a KO victory, but his last notable fight came in a decision defeat to Britain's Martin Murray back in June of 2018. Garcia has never been stopped so it would be a statement if Smith could get the 39-year-old out of there.
Rough and rugged Gabriel Rosado (24-12-1) has fought the best of the best and will be in action again in Phoenix when he squares off against Humberto Gutierrez Ochoa (33-8-2) in a ten-round Super Middleweight contest. Rosado is coming off a loss on points to Maciej Sulecki back March and will be looking for his first win since 2017 here. Ochoa, a former Super Featherweight, is coming off a loss to unbeaten Christian Mbilli back in March.
The other live float of the night sees Welterweight prospect Reshat Mati (5-0) go head to head with Rakim Johnson (6-8-1) in a six-round fight at Welterweight.