Andy Ruiz Jr. provided proof Friday of all the hard work he has put in to prepare for his fight against Chris Arreola.

The former heavyweight champion came in at 256 pounds, 27½ pounds less than he weighed the day before his loss to Anthony Joshua in their 12-round rematch 16 months ago in Diriyah, Saudi Arabia. Ruiz weighed 283½ pounds for his rematch with Joshua, 15½ more than Ruiz officially weighed for his historic upset of the previously unbeaten British superstar in June 2019 at Madison Square Garden in New York.

The 40-year-old Arreola also was significantly lighter Friday than he was for his last fight.

Arreola stepped on the California State Athletic Commission’s scale at a career-low 228½ pounds. The Riverside, California, native weighed 244 pounds prior to his 12-round, unanimous-decision defeat to Adam Kownacki in August 2019 at Barclays Center in Brooklyn.

Ruiz and Arreola are scheduled to square off Saturday night in the 12-round main event of a four-fight FOX Sports Pay-Per-View show at Dignity Health Sports Park in Carson, California.

The 31-year-old Ruiz hasn’t fought since losing a unanimous decision to Joshua, who regained the IBF, IBO, WBA and WBO belts from Ruiz in their second fight in December 2019. Arreola, who hasn’t boxed since his all-action brawl with Kownacki, will end a 20-month layoff.

Ruiz will fight for the first time with his new trainer, Eddy Reynoso, in his corner.

Reynoso, most known for training Canelo Alvarez, helped Ruiz rededicate himself to the sport.

Ruiz’s official weight Friday was close to his weight for his first title fight, 255¾ pounds. He lost a 12-round majority-decision to New Zealand’s Joseph Parker (28-2, 21 KOs) in that December 2016 bout in Auckland.

The weights for the three Ruiz-Arreola pay-per-view undercard bouts are listed below.

FOX Sports Pay-Per-View (9 p.m. ET; 6 p.m. PT; $49.99)

Omar Figueroa Jr. (28-1-1, 19 KOs), Weslaco, Texas, 146½ pounds vs. Abel Ramos (26-4-2, 20 KOs), Casa Grande, Arizona, 146½ pounds, 12 rounds, welterweights.

Sebastian Fundora (16-0-1, 11 KOs), Coachella, California, 152¾ pounds vs. Jorge Cota (30-4, 27 KOs), Los Mochis, Mexico, 153½  pounds, 12 rounds, junior middleweights.

Jesus Ramos (15-0, 14 KOs), Casa Grande, Arizona, 150 pounds vs. Javier Molina (22-3, 9 KOs), Norwalk, California, 149¼ pounds, 10 rounds, junior middleweights.

FOX (7 p.m. ET; 4 p.m. PT)

Erislandy Lara (27-3-3, 15 KOs), Guantanamo, Cuba, 159½ pounds vs. Thomas LaManna (30-4-1, 12 KOs), Millville, New Jersey, 159 pounds, 12 rounds for the vacant WBA world middleweight title.

Eduardo Ramirez (24-2-3, 11 KOs), Los Mochis, Mexico, 125½ pounds vs. Isaac Avelar (17-2, 10 KOs), Aguascalientes, Mexico, 125 pounds, 12 rounds for the vacant WBA interim featherweight title.

FOXsports.com & FOX Sports app (4:40 p.m. ET; 1:40 p.m. PT)

Adrian Granados (21-8-2, 15 KOs, 1 NC), Cicero, Illinois, 146½ pounds vs. Jose Luis Sanchez (11-1, 4 KOs), Albuquerque, New Mexico, 146¼ pounds, 8 rounds, welterweights.

Carlos Negron (22-3, 18 KOs), Villalba, Puerto Rico, 235¾ pounds vs. Scott Alexander (16-3-2, 8 KOs), Los Angeles, 235 pounds, 8 rounds, heavyweights.

Fernando Molina (5-0, 3 KOs), Guadalajara, Mexico, 133½ pounds vs. Prisco Marquez (4-2-1, 1 KO), Austin, Texas, 135 pounds, 6 rounds, lightweights.

Anthony Garnica (5-0, 3 KOs), Oakland, California, 125¼ pounds vs. Jesse Bazzi (1-1, 0 KOs), Dearborn, Michigan, 126½ pounds, 4 rounds, featherweights.

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