Notes: Russian prospect Butaev lands on Spence-Algieri card

Welterweight prospect Radzhab "The Python" Butaev will be a late addition to Saturday's Errol Spence Jr.-Chris Algieri undercard in Brooklyn, New York. DiBella Entertainment

A few notes from around the boxing world:

• Promoters Lou DiBella and Fight Night Promotions announced they have signed 23-year-old Russian welterweight prospect Radzhab "The Python" Butaev (1-0, 1 KO) to a co-promotional deal and he will fight South Carolina's TyKeem Sadler (6-1, 4 KOs), 20, on the Errol Spence Jr.-Chris Algieri undercard Saturday night at the Barclays Center in Brooklyn, New York. Butaev was reportedly 304-12 with 164 knockouts as an amateur. He also was 9-1 in the World Series of Boxing. "Though I could have competed in the [2016] Olympics, I felt that my career really wouldn't excel until I turned pro in the United States," Butaev said. "I know that I am in good hands with DiBella Entertainment and Fight Promotions Inc., who have developed the careers of many of my countrymen and contemporaries whom I knew well in the amateurs. I am excited to demonstrate my skills in front of an American audience in Brooklyn. On [Saturday] and beyond, they can expect great things from me."

• Junior bantamweight titlist McJoe Arroyo (17-0, 8 KOs), of Puerto Rico, suffered a left hand injury and has withdrawn from his defense against mandatory challenger Jerwin Ancajas (24-1-1, 16 KOs), of the Philippines. They were due to meet Saturday in Manila but Arroyo hurt his hand last week and pulled out this week. According to the IBF, Arroyo is eligible for a medical extension to his mandatory and would be required to face Ancajas upon his return, otherwise he would be stripped of the belt. Arroyo won a vacant 115-pound belt by 10th-round technical decision against Artur Villanueva last July and the fight with Ancajas was supposed to be his first defense. Arroyo is the twin brother of McWilliams Arroyo, who challenges flyweight world champion Roman "Chocolatito" Gonzalez for the title on April 23.

• HBO will replay Manny Pacquiao-Timothy Bradley Jr. III on Saturday night (10 ET/PT) with additional corner audio from Bradley trainer Teddy Atlas that was not originally seen during last week's live pay-per-view presentation. The debut of "Face with Max Kellerman: Canelo/Khan" immediately follows. HBO Latino will also replay the fight but beginning at 11:15 p.m. ET/PT it will also replay all three of the pay-per-view undercard fights: Gilberto Ramirez's super middleweight world title decision win against Arthur Abraham, Oscar Valdez's sensational fourth-round knockout of former featherweight titleholder Evgeny Gradovich and junior welterweight Jose Ramirez's 10-round decision against tough Manny Perez.