Here’s a preview and picks for UFC 224 in Rio de Janeiro

A breakdown of the fights on the main card of Saturday’s UFC 224 card at Jeunesse Arena in Rio de Janeiro, with picks from the Review-Journal’s Adam Hill and Heidi Fang:

Amanda Nunes (15-4) vs. Raquel Pennington (9-6)

Class: For Nunes’ women’s bantamweight title

Line: Nunes -900

Storyline: While Nunes has seized control of the division, Pennington has quietly been waiting for her shot. Pennington extended her winning streak to four and claimed her spot as a top contender by beating former champ Miesha Tate in November 2016, but has been out of action ever since. She gets the opportunity to fight for the belt here after a proposed superfight between Nunes and featherweight champion Cris “Cyborg” Justino fell through. The long layoff could be a concern for Pennington here against Nunes, who is a notoriously fast starter. If she can get through the initial onslaught, Pennington has a chance. Nunes has started to fix some of her conditioning issues as she gets more accustomed to five-round fights, but it’s still a concern. So is inconsistency. Pennington may be a live dog for those who like to take a chance.

Hill’s Pick: Nunes by second-round knockout

Fang’s Pick: Nunes by third-round knockout

Ronaldo “Jacare” Souza (25-5, 1 No Contest) vs. Kelvin Gastelum (15-3, 1 No Contest)

Class: Middleweights

Line: Souza -145

Storyline: Souza is flat-out lethal when the fight hits the mat. That’s no secret, but it still seems Souza’s overall game gets missed by some casual observers of the sport. He has used his vastly improved striking skills to win 10 of his last 12 fights, with the only losses coming to middleweight champ Robert Whittaker and the man he will fight for the belt next month, Yoel Romero. Souza wants to remain in that mix and he will almost certainly do that if the fight hits the ground. Gastelum is a very worthy adversary, however, and one who thrives at thwarting takedown attempts and making opponents pay for even trying. This is a very good matchup for him, but that only applies as long as he really can stay off the mat

Hill’s Pick: Souza by second-round submission

Fang’s Pick: Gastelum by decision

Mackenzie Dern (6-0) vs. Amanda Cooper (4-3)

Class: Women’s strawweights

Line: Dern -240

Storyline: Two of the biggest questions about Dern as a potential superstar in mixed martial arts are actually quite related. There has been a great deal of speculation about her work ethic considering she is already famous and successful in the jiu-jitsu world and has expressed a desire to make a big splash and retire young now that she is in MMA full-time. The other concern is her ability to make weight consistently, which could be magnified if there is any slippage in her training. She came in seven-pounds over on Friday. That’s certainly a red flag. Dern’s long-awaited UFC debut in March went fine as she escaped with a split-decision win over Ashley Yoder. She’s going to have to show more if she wants to live up to the potential that has been affixed to her since she even discussed a transition to MMA. Dern is a potential superstar and if she’s on her game, this should be a showcase. The number on the scale Friday should be a big red flag to any potential bettors, however.

Hill’s Pick: Dern by second-round submission

Fang’s Pick: Cooper by decision

John Lineker (30-8) vs. Brian Kelleher (19-8)

Class: Bantamweights

Line: Lineker -250

Storyline: Lineker has never really deviated much from what made him popular as he rose through the ranks. He is all power, all the time. The Brazilian does to a pretty good job of mixing in body shots and not simply head-hunting, which makes him even more dangerous. Lineker does still have occasional conditioning issues, which could play a big role here. Kelleher is also an ultra-aggressive fighter, though he may be able to sustain the attack longer than Lineker. That’s where Kelleher could take control of the fight. If his cardio holds up better, Kelleher becomes a live dog.

Hill’s Pick: Kelleher by decision

Fang’s Pick: Lineker by third-round knockout

Vitor Belfort (26-13, 1 No Contest) vs. Lyoto Machida (23-8)

Class: Middleweights

Line: Machida -270

Storyline: An unofficial old-timers’ fight will open the main card. The best days are well in the past for both fighters, but Machida pulled off a stunning win last time out when it seemed like he was matched up to fail against rising star Eryk Anders. The win snapped a three-fight streak of knockout losses and showed the former light heavyweight champion may have something left in the tank. He will get a chance to put together back-to-back wins for the first time since 2014 against Belfort, who once again says he will retire after this fight. That seems to be his narrative in every bout. Another former champion, he won for the first time since 2015 when he beat Nate Marquardt last June. It’s impossible to tell which Belfort will show up on a given night at this point in his career, so he could be a live dog. Machida is just as likely to send him out to pasture with a crushing knockout. It might be better to sit this one out as a bettor and just enjoy the spectacle.

Hill’s Pick: Machida by second-round knockout

Fang’s Pick: Machida by decision

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Adam Hill/Las Vegas Review-Journal