The 36-year-old middleweight/light heavyweight contender is easily one of the UFC's most recognizable names and faces, but there's only so much the UFC can do to market him as a true title contender if he doesn't win his next bout.
To be fair, just about any fighter would have lost the two fights that make up Sonnen's current two-fight skid. His first loss was to the longest reigning champion in UFC history, Anderson Silva. His second was against the man that will probably break all of Silva's records, Jon Jones.
Sonnen's detractors would love to say that precludes Sonnen from ever competing for UFC gold again. That's not really the case, though. With Silva now dethroned in the middleweight division, there's a very real possibility "The Gangster from West Linn, Oregon" could make a run at 185 pounds again.
Realizing this opportunity, Sonnen has already declared his intentions to go back to middleweight after defeating Shogun on "UFC Tonight," per MMAWeekly:
"I’ll return to middleweight after beating Shogun,” said Sonnen on Tuesday night’s edition of UFC Tonight. There’re two guys I want to get matched up with: Vitor Belfort, because he’s awesome and he’s on an incredible roll. And Wanderlei Silva, who I’ve heard is going back to middleweight.
“The landscape has completely changed. I’ve got a new contract and I’m returning to the weight class."
However, a loss to Rua would put any of Sonnen's title hopes to rest.
Rua himself is teetering on the edge of relevance entering Saturday's fight. The last time he put together a two-fight win streak was in 2009 when he defeated Mark Coleman at UFC 93 and Chuck Liddell at UFC 97.
Since then, he has alternated wins and losses in his last seven fights. Among the wins was a knockout victory over Lyoto Machida that crowned him as the light heavyweight champion. His other wins have come against Forrest Griffin and Brandon Vera.
Who wins Saturday night's fight?
While he's always been a fan favorite and legend of the sport, it's tough to make the argument that he's still an elite contender anymore. A loss to Rua now is much more inexcusable to fans and UFC brass than it was just two or three years ago when he was still the fierce man who knocked out Machida.
Sonnen won't necessarily be forced to retire with a loss. His larger-than-life persona and ability to hype a fight will still make him a draw.
He mentioned taking on 37-year-old Wanderlei Silva in his return to middleweight. That's a fight that could headline a smaller card based on their high-profile status regardless of title implications.
However, Sonnen has always been about earning UFC gold. As much as he loves the spotlight, he's a fighter that wants to prove he's the best. Defeating Shogun Rua on Saturday night is his last chance to prove that he deserves to be on the title track once again.