5 for Fighting!: Five key storylines heading into UFC Fight Night 62

Ultimate Fighting Championship (UFC) touches down in Brazil for the second time in the span of a month when the Maracanazinho Gymnasium in Rio de Janeiro plays host to the injury-plagued UFC Fight Night 62 card.

A rematch of top-ranked bantamweights Urijah Faber and Raphael Assuncao was originally tapped as the show's main event, but instead Brazilian fans get a five-round welterweight bout featuring the return of former title challenger Demian Maia. The 37-year-old has been on the mend following a battle with staph infection.

Maia's opponent is undefeated No. 15-ranked welterweight Ryan LaFlare. Like Maia, the Blackzilians fighter is an astute ground fighter, and has masterfully neutralized all four of his Octagon foes.

In the co-main event of the evening, Josh Koscheck fills in for an injured Ben Saunders against dangerous Brazilian jiu-jitsu black belt Erick Silva. "Kos" recently fought at UFC 184, and was choked out by Jake Ellenberger. Silva, on the other hand, last fought in Brazil back in Dec. 2014, submitting Mike Rhodes with ease.

Further down the fight night card are pivotal match ups in the lightweight and women's bantamweight divisions. Here are the five storylines you need to know as we head south of the equator once again for some mixed martial arts (MMA) action.

5. Amanda Nunes attempts to climb back into the mix of contenders at 145 pounds

"The Lioness" was humbled by Cat Zingano at UFC 178 in Sept. 2014. Prior to her beatdown at the hands of "Alpha," Nunes was a destroyer of female fighters.

The American Top Team (ATT)-trained knockout artist compiled a magnificent highlight reel in 2013 after she took out Sheila Gaff and Germaine de Randamie in the first round.

Nunes will try to get back in the win column against former Invicta FC competitor Shayna Baszler. "The Queen of Spades" has consistently fought top-level competition through her MMA career. Baszler, though, hasn't had the easiest run of late.

The 34-year-old has dropped her last two fights to Brazilian slugger Bethe Correia and former No. 1 women's bantamweight contender Alexis Davis. When Baszler is at her best is when she's wrestling her opponent to the mat and utilizing her jiu-jitsu.

Though she can take a punch, Baszler has recorded a whopping 14 submission victories throughout her career. With both women in need of a win, I'd expect these two to display a sense of urgency early.

4. Lightweight Gilbert Burns aims to remain undefeated as he faces Alex Oliveira

Burns is undefeated (2-0) inside the Octagon and won in his last outing against Christos Giagos, which was at lightweight.

It's hard to get "Durinho" off of you when he is in top control. A former gold medalist in the World Jiu-Jitsu Championships, Burns has stymied strikers like Giagos and Andreas Stahl in the past.

Burn was slated to tangle with former Strikeforce lightweight champion Josh Thomson at this event, but after "The Punk" bowed out with an injury he was replaced with a highly-formidable Octagon newcomer.

Oliveira is a vicious striker, who possesses dynamite in both hands. The "Cowboy" has accumulated eight knockouts in 10 victories. Check out his mauling of Douglas Aparecido here.

Additionally, he's only be taken the distance three times in his whole career. It's hard to tell how Oliveira will stack up with the Blackzilians fighter just yet, but a finish by either man seems very befitting.

3. High-level jiu-jitsu aces Tony Martin and Leonardo Santos meet in a battle of up-and-coming lightweights

The ATT member Martin replaces an injured Matt Wiman and is looking to build off of an impressive kimura victory over third-degree Brazilian jiu-jitsu black belt Fabricio Camoes.

The win couldn't have come at a much better time for Martin, who was facing a potential dismissal from the UFC after coming up short in his first two Octagon appearances. The 25-year-old has slowly improved upon a previously weak striking game. Martin's revamped gameplan was on display in a loss against Iranian muay-thai tactician Beneil Dariush.

An upgraded arsenal of attacks will be important if he hopes to have success against Leonardo Santos. The Sao Paulo submission artist has made a career out of snatching up chokes. Santos has racked up eight wins by submission, including one over team Blackhouse striker William Macario in June 2013, which saw him claim The Ultimate Fighter (TUF) Brazil 2 crown.

Even if Santos is put on his back, and that's a big if, the Rio de Janeiro native is very comfortable there. The 35-year-old sports solid takedown defense, and six victories by triangle choke.

Looks like someone will be at a loss for words, and air, come March 21.

2. Is this Josh Koscheck's swan song?

The 37-year-old former welterweight title challenger returned from a elongated absence from Octagon to face fellow struggling 170-pounder Jake Ellenbeger at UFC 184. Kos couldn't contain the bleeding, and was handed a fourth-straight loss by "The Juggernaut."

Now, with his deal set to expire the night he takes on burgeoning Brazilian contender Erick Silva, will Koscheck potentially go out a winner or a loser? The former Division I All-American wrestler got back to his roots against Ellenberger, but came up short.

Koscheck's bread and butter is also his heavy right hand. The division, though, has passed him by over the last three years as more athletic combatants began to emerge. Silva is one of them.

The 30-year-old has shown a lot of promise so far in his four-plus year UFC tenure, but has never been able to string together multiple victories. Silva has lost to the welterweight division's best such as Jon Fitch and Dong Hyun Kim.

Where one fighter lacks momentum, the other is in desperate need of it. Silva is well-rounded and has gained a finish in each of his five UFC wins. Koscheck would appear to be ripe for the picking. We'll see if Koscheck is a survivor on Saturday.

1. Demian Maia reenters the 170-pound title sweepstakes

Despite missing nearly nine months with a debilitating injury, Maia comes back to a division in flux, with his rank still intact. The former middleweight successfully carved out a niche at welterweight over the past few years, before stumbling against the division's elite.

The Brazilian initially garnered a lot of attention early on for his world-class jiu-jitsu credentials, but has only been able to snag a submission in one of his last 14 outings. Well, if Maia was thinking he'd add another victim to his MMA resume in Ryan LaFlare, he's sorely mistaken.

Since the Blackzilians product burst onto the scene in April 2013, he's won four-straight fights to keep his undefeated professional record intact. Over the last two years, LaFlare has roughed up John Howard, Court McGee, Santiago Ponzinibbio and Ben Alloway. The 31-year-old has a game predicated on power wrestling and crisp striking.

LaFlare is a southpaw whose outstruck all four of his UFC opponents and also averages close to five takedowns per bout. In a nutshell, the Florida-based fighter is very similar to Maia, except he has youth on his side. It will be the crafty veteran versus the upstart contender down in Rio.