It's International Fight Week in Las Vegas. This is typically when we see the biggest and brightest UFC stars come out to showcase their skills. Last year, UFC 200 was originally expected to deliver two marquee title fights in Miesha Tate vs. Amanda Nunes and Daniel Cormier vs. Jon Jones. But after a failed drug test the week of the fight, Jones was forced out of the match, making UFC call on one of its veterans to take on Cormier instead: Anderson Silva.

This year, the main fight card was also expected to bring two title fights. It still will, but one is going to be an interim title fight instead. With that, we take a look at the biggest storylines you need to know ahead of UFC 213 on Saturday night in Las Vegas.

1. The card has lost some luster: UFC 213 was expected to bring us two titles fights at 135 pounds with Amanda Nunes defending her title against Valentina Shevchenko and Cody Garbrandt settling the score against T.J. Dillashaw. But with Garbrandt having to undergo back surgery, the fight was scrapped, leaving a hole in the co-main event. Plus, Donald Cerrone and Robbie Lawler were expected to slug it out in the welterweight division, but a blood infection forced "Cowboy" out. Still, there are some big names fighting on Saturday night.

2. The interim title fight will be fire: The replacement fight for Garbrandt-Dillashaw couldn't get much better than what UFC gave us. Yoel Romero will battle Robert Whittaker for the interim middleweight crown while Michael Bisping recovers from surgery. Two of the fastest rising fighters in the company, Romero and Whittaker will enter the cage riding a combined 15-fight winning streak. It's hard enough to win two or three fights in a row in UFC, but these guys (Romero 8, Whittaker 7) have been two of the best in the company of late. Whittaker jumped some top contenders for the title when he surprisingly stopped Jacare Souza in April by TKO. Romero is coming off a highlight-reel TKO of Chris Weidman last November.

3. A grudge match at heavyweight: Alistair Overeem and Fabricio Werdum have fought twice before but never under the UFC banner. Now, the two will fight for the likely chance to challenge Stipe Miocic next. Despite both men being knocked out by Miocic within the last year, the heavyweight division has been so top-heavy that no one else can really stake a claim to the No. 1 contender's slot, especially with Cain Velasquez still inactive. Now, with both fighters having a recent win under their belts (Werdum beating Travis Browne by unanimous decision and Overeem knocking out Mark Hunt), the winner can look forward to facing Miocic again later on this year.

4. There's a veteran lightweight showdown: Anthony Pettis is leading a rather peculiar path. The former 155-pound champion lost his belt in 2015 to begin a three-fight losing streak. Then he decided to move down to 145 pounds and see if he could make a run at the title there. But in just his second bout at featherweight, which became an interim title fight, Pettis failed to make weight before getting pummeled by Max Holloway. Now, Pettis is back up to 155 and challenging veteran and fan favorite Jim Miller, who had his three-fight winning streak snapped by a majority decision loss to Dustin Poirier in February. It feels like Pettis is fighting for his career a bit here because a 1-5 mark over six fights does not a career make.

5. The baddest woman on the planet? Amanda Nunes is quickly becoming one of the top power punchers in the women's bantamweight division. She's coming off back-to-back wins where she pummeled Miesha Tate and Ronda Rousey, scoring a submission win over Tate for the title and a knockout of Rousey in the first round. This time, she gets an opponent she faced last year in Shevchenko where she won by unanimous decision. Since 2011, Shevchenko is the only fighter to take Nunes the distance in MMA, but if Nunes is able to crack the code and score another stoppage victory on Saturday, it's going to be hard to ignore the path of destruction she's left in her wake over the past three years.