SAN ANTONIO – Rey Vargas wasn’t exactly enthralled by Mark Magsayo’s performance against Gary Russell Jr.

The undefeated Filipino fighter dethroned boxing’s longest-reigning champion by majority decision January 22 at Borgata Event Center in Atlantic City. Vargas, who will challenge Magsayo for his WBC featherweight title Saturday night, still came away more impressed with how an injured Russell remained competitive while basically boxing with one arm for eight-plus rounds.

“Magsayo did what he had to do in order to win the fight,” Vargas told krikya360.com. “Gary Russell Jr. fought really well, considering that he was either injured beforehand or injured his [shoulder] during the fight. So, he had a good showing, too. But Magsayo, even though he didn’t shine or stand out a lot against Gary Russell Jr., and it wasn’t a lopsided fight, he did what he needed to do to prevail and he showcased power that needs to be respected.”

Russell worsened an existing injury to his right shoulder early in the fourth round of his 12-round title defense against Magsayo. The resourceful southpaw still managed to defend himself well, though his offense was mostly restricted to occasional left hands after the fourth round.

Judges Mark Consentino (115-113) and Eugene Grant (115-113) scored seven rounds apiece for Magsayo, who was the aggressor for most of their 126-pound championship match. Judge Lynne Carter scored the action even, 114-114.

Mexico’s Vargas isn’t entirely sure who won because he didn’t watch the whole Magsayo-Russell bout.

“Look, I didn’t watch the fight from wire to wire,” Vargas said. “I saw some rounds, so I wouldn’t be able to tell you I’m the authority on that fight, to tell you whether [Magsayo] deserved to win or not. But what I can tell you from what I saw was that Gary Russell was the one who shined defensively. He really put on a really good performance in that aspect of the fight. But as far as whether Magsayo deserved it or not, since I didn’t watch the fight in its entirety, I wouldn’t be able to tell you definitively about that.”

Most oddsmakers have installed Vargas (35-0, 22 KOs) as a slight favorite to beat Magsayo (24-0, 16 KOs) in their “Showtime Championship Boxing” main event at Alamodome (9 p.m. ET). Vargas, a former WBC super bantamweight champ, is the WBC’s mandatory challenger for Magsayo’s title.

Brandon Figueroa (22-1-1, 17 KOs), a former WBC 122-pound champ from Weslaco, Texas, will face Phoenix’s Carlos Castro (27-1, 12 KOs) in Showtime’s co-feature Saturday night, a 12-round WBC featherweight elimination match. The opener of this tripleheader will pit Indianapolis’ Frank Martin (15-0, 11 KOs) against Dominican veteran Jackson Marinez (19-2, 7 KOs) in a 10-round lightweight bout.

Keith Idec is a senior writer/columnist for krikya360.com. He can be reached on Twitter @Idecboxing.