Exciting, unbeaten Rios 28-0-1 (21) puts his WBA World Lightweight title on the line, having won the strap in February defeating Miguel Acosta by TKO in Las Vegas and following that up in July with a sensational first defence against Urbano Antillon, claiming a KO victory in a thrilling three round slug fest in Carson, California.
John Murray 31-1 (18), featuring in his first world title fight, is coming off a devastating loss to fellow Brit Kevin Mitchell in July, an eighth round TKO having been floored by the Londoner moments earlier in the British Fight of the Year.
Neither man is difficult to hit which makes for a fascinating and, probably, brutal contest. Murray typically takes a few rounds to warm to the task, a luxury Rios does not afford many of his opponents, fourteen of his previous victims failing to see the fourth round.
In the battle of KO's, Rios comes out top with 72% against Murrays 56%. Just sixteen months separate the men in terms of age. Murray has a slight experience advantage with three fights more but the Oxnard banger has clearly fought in higher company and, crucially, won those key fights.
In terms of character, the two men are distinctly different. Rios is a practical joker, live wire and centre of attention in the gym. Murray is more serious, focussed.
Rios has shared trainer Robert Garcia with Margarito in the build-up the MSG card, some questioning if the lack of Garcia's undivided attention would have a detrimental effect. Murray had a controversial and high profile split from trainer Joe Gallagher in the aftermath of the Mitchell loss, dispensing of Gallagher's services by text message but later reversing that decision and going back to Gallagher's Denton gym, the site where Billy Graham and Ricky Hatton used to be based.
The match-up presents Murray an opportunity he probably should not be getting at this time, and this makes him a more dangerous opponent. Kevin Mitchell should be across the ring from Rios on Saturday night but his well documented problems with the police and issues in his personal life have prevented him travelling to the US in what is surely his boxing prime.
Murray shouldn't suffer stage fright however. He fought on the 2007 Mayweather-De La Hoya undercard in Las Vegas and was back in the MGM Grand later the same year to score a decision victory the night before fellow Mancunian Ricky Hatton lost to Mayweather in the same venue. Murray also claimed victories on the road in Florida and Quebec in 2005.
Outside the ring, both men have had their problems. Rios suffered reputational damage in the aftermath of his ill-advised 'joke' at the expense of future hall of fame shoe-in Freddie Roach, but his public apology and subsequent contrition went some way to making amends.
Murray, who was stripped of his British title in 2009 having failed to make weight in his title defence against Scott Lawton, went on to win the title back just four months later before adding the European title in his following fight, beating the well-respected Gary Buckland, now holder of the British Super-Featherweight crown.
The bout is likely to be fought at close quarters, Rios looking to land barrages of heavy hooks and uppercuts. Rios hits very hard, and will surely go after Murray early, looking to force the Brit on to the back foot. Murray has the ability to wear the champion down if he survives the inevitable early onslaught, but it's a huge 'if'. Murray has been caught and marked-up by far less impressive fighters than Rios in his career to date.
The smart money is therefore on the champion to retain, probably by TKO in the first half of the fight. It is difficult to build a case for Murray. Rios is strong, busy, aggressive and has house advantage on a Top Rank card. And, he's the champ. Murray has heart, a strong chin and pours on the pressure. But he must improve his movement and work rate if he is to have a chance of pulling off what would be a famous, against-the-odds victory.
However long it lasts and whatever the outcome, it should be fun!