UFC 306 primer: Unique fight card inside Sphere offers no shortage of excitement

At last, UFC 306 is here. And you know what that means: it's Sphere time.

Not since “Fight Island” has the UFC built so much anticipation around the role of the venue and presentation in one of its events. That turned out to be a bit of a letdown. (No beachfront Octagon. No palm trees. Not even a real island.) But this one? A UFC event in the immersive experience of Las Vegas’ Sphere? It promises to be, if nothing else, very different.

We’ll have to wait until Saturday to discover exactly what that means, but there is plenty to get excited about on this fight card. Just maybe don’t get too bogged down in the mind-bending marketing ploy of a fight to celebrate Mexican Independence Day … in Las Vegas … sponsored by Saudi Arabia.

Here’s what’s on tap for the UFC 306 main card:

Ronaldo Rodriguez vs. Ode Osbourne

Who they are: Rodriguez is still relatively new to the UFC, but he's on a six-fight heater overall and the last three have ended inside the distance. He's also nicknamed "Lazy Boy," so that's pretty memorable. Osbourne is staring at the dreaded and often decisive three-fight losing streak if he can't claw his way to a win here.

Why it matters: Rodriguez, who hails from Mexico, is a fighter on a winning streak. Now, on this event to celebrate Mexican Independence Day, he faces an opponent on a losing streak. Here's where a cynical man might suggest it's a bout designed to get Mexico a win and fire up the crowd at the start of the pay-per-view. Osbourne is better than his recent record suggests, but it's probably win-or-get-fired time here.

Daniel Zellhuber vs. Esteban Ribovics

Who they are: A classic Mexico versus Argentina rivalry in this lightweight bout. Zellhuber hasn't lost since his UFC debut. And hey, that could happen to anyone, since Octagon jitters are a real thing. Ribovics suffered the same fate in his first UFC bout. Just like Zellhuber, it's the only loss of his pro career.

Why it matters: These guys are in very similar spots in their respective careers. Just a couple under-30 lightweights trying to make their way in arguably the toughest division in the entire sport. Throwing them in there together seems like a test to find out which is the more promising prospect right now.

Brian Ortega vs. Diego Lopes

Who they are: Ortega is the former title challenger trying to hang onto his position as one of the top guys at featherweight by fending off these young hitters. Lopes is the guy with the emo hair who keeps overperforming in increasingly tough fights.

Why it matters: Every time Lopes fights and wins in the UFC there's a creeping sense of "hold on this guy might actually be good." Ortega is a significant step up from the competition he's faced so far, making this the toughest test yet for that particular hypothesis. If Lopes wins this one, he probably enters the title contender conversation. If he doesn't, fans might decide he's just another fun guy to have at 145 pounds.

Alexa Grasso vs. Valentina Shevchenko

Who they are: Grasso is the women's flyweight champion. Shevchenko is the woman she beat to claim the title in the first place. That was a surprising upset all on its own. Then they fought again and ended in a draw. Now, for the first time since 2016, Shevchenko heads into a UFC fight as a betting underdog.

Why it matters: That shiny gold belt, for one thing. But also this is the trilogy fight where Grasso can finally put to rest any suggestion that she might have just gotten lucky once and doesn't really deserve to be called a champion. For Shevchenko, it's a chance to show her time at the top isn't done just yet. Or is it?

Sean O’Malley vs. Merab Dvalishvili

Who they are: O'Malley is the men's bantamweight champ. He's also the most popular fighter on this card and the driving force behind ticket and pay-per-view sales. Dvalishvili is a legitimately dangerous challenger for him. He's won 10 straight fights and hasn't ever looked even the least bit winded in the process. He's one of those fighters whose motor is simply set to a higher speed — and he knows how to use that as a weapon of its own.

Why it matters: O'Malley's popularity has helped turn the 135-pound title into big business for the UFC. Here he faces a kind of test he hasn't really had to pass yet. Dvalishvili is the kind of wrestling-based fighter who is constantly in your face, wearing you down with pace and pressure. O'Malley would much prefer to keep him at a safe distance where he can employ his reach and slick striking to great effect. Now it's just a question of who will have his way.