Three of the four recognized heavyweight titles will be at stake on Saturday when British star Anthony Joshua returns in front of an expected crowd of 90,000 at London's Wembley Stadium.

The fact that the fourth title -- the WBC strap owned by fellow unbeaten Deontay Wilder -- isn't on the line after very public talks fell apart in recent months for a fall unification bout has done a decent job in overshadowing the danger of Joshua's return. Yet the unified WBA/WBO/IBF titleholder faces a stiff test nonetheless in WBA mandatory opponent and former world title challenger Alexander Povetkin (34-1, 24 KOs).

Armed with a new three-year deal with promoter Matchroom Sport and firmly entrenched as the sport's biggest star globally, the 28-year-old Joshua (21-0, 20 KOs) doesn't look at choosing Povetkin as necessarily risking a future fight with Wilder (40-0, 39 KOs), who is currently negotiating a bout with lineal champion Tyson Fury for December. Joshua also denied that choosing Povetkin had everything to do with the fight being used as a launching pad for the streaming service DAZN, which commenced in America on Sept. 10 ahead of Saturday's debut card (4:30 p.m. ET).

Respect box? Subscribe to my podcast -- In This Corner with Brian Campbell -- where we take an in-depth look at the world of boxing each week.

"My psyche has changed. I'm not interested in who I am fighting and if they are banana skin slips anymore," Joshua told CBS Sports in July. "I'm interested in where my goal is and what I'm destined to do. So I've kind of had to learn. I'm still physically a danger but I've had to step up my psyche.

"I'm just going to focus on Povetkin but ultimately my goal beyond that is to fight for the undisputed championship of the world. Regardless of banana skin, if I slip, I'm not going to stay down for the 10 count. I'm going to get up, brush that off and still stay on my course for Deontay Wilder."

Povetkin, a 39-year-old former Olympic gold medalist for his native Russia, brings an impressive resume and a dangerous mix of power and amateur pedigree. Yet, despite his only pro defeat coming by decision against then-unified champion Wladimir Klitschko in 2013, Povetkin has been tabbed as a massive betting underdog which, in light of Joshua's vulnerable chin, could make him a live dog.

"I think right now I'm in one of the best shapes of my career," Povetkin said at Wednesday's media day in London. "Although I'm 39 right now, I feel like I'm 25. I have Anthony Joshua in my sights and that's all I'm focused about is this fight. This is very important for me and of course this will be one of my last chances to make an impact and I will."

Joshua-Povetkin fight card

Favorite Challenger Weightclass Anthony Joshua (c) -1100 Alexander Povetkin +650 Unified heavyweight titles Luke Campbell -450 Yvan Mendy +325 Lightweight Lawerence Okolie -300 Matt Askin +225 Cruiserweight

For Povetkin to even be in this fight as a mandatory challenger has created plenty of debate considering his pair of failed drug tests (and minimal punishment) over the past two years, including one that cost him a 2016 title shot in Moscow against Wilder.

Joshua's camp was well aware coming in of Povetkin's reputation and that the danger he brings goes beyond just the power in his right hand. To counteract that, Joshua promoter Eddie Hearn paid for additional random testing during training camp beyond what was already being administered by the Voluntary Anti-Doping Agency.

While Hearn was confident in the amount of testing, saying, "it's a 12-week process … so you can't cheat," Joshua wasn't as worried.

"What I've learned is that I don't tend to care anymore about what other people are doing and their situation," Joshua said. "What Povetkin and other people who have been found using banned substances have been doing, it's between them and their team. I don't know the ins and outs or what he was caught for but what I do is invest back into the show and have independent drug testers to visit himself and visit myself and we enroll in a new, independent anti-doping agency.

"They should be testing him and if they are, he should be clean and I'm confident that he's a clean fighter right now. I think he made a mistake then and he's got it right. All these banana skins -- is he on PEDs, is he on banana skins, is he fighting Wilder -- the focus is on me. I'm going to be the man in the mirror and be at my best for this fight."

Joshua's American broadcasting deal with Showtime expired following his March unification win over Joseph Parker. A bidding war was expected to ensue between Showtime and HBO until Hearn made the massive announcement he had signed an eight-year, $1 billion deal with DAZN to promote fights in America. Originally, Hearn said Joshua was not part of that deal, per se, but later conceded DAZN pushed for Joshua's next fight to be used as the face of the U.S. launch.

In April 2017, Joshua cemented his bid for worldwide stardom when he got off the deck to knock out Klitschko in front of 90,000 at Wembley Stadium. Although his next two bouts, a TKO of Carlos Takam and a decision win over Parker, both set indoor boxing attendance records, Joshua was criticized by some for looking flat and less aggressive. Others contended he was looking to box more in order to protect himself from counter fire.

Asked whether he's exploring a more defensive style moving forward, Joshua said it has more to do with him being forced to learn on the job, especially after his 2016 title win against Charles Martin (in just his 16th pro fight) came earlier than expected.

"From the amateurs, it took me three years to go from walking in the gym to get to the professionals," Joshua said. "In the pro ranks, it took me three years from having my first fight to fighting for the IBF strap so I have had to learn along the way. There has always been a fight after a fight. 'Anthony Joshua is fighting Charles Martin and once he beats him, he's fighting [Dominic] Breazeale. And once he fights Breazeale, he's fighting [Eric] Molina. And if beats Molina, Klitschko is waiting ringside to get in the ring.' And after I fought Klitschko, I was going to fight [Joseph] Parker or Wilder, so there has always been someone after."

Knowing that Povetkin's aggressive style may force him into a firefight if he's not careful, Joshua reminded reporters at Wednesday's media day of his willingness to trade if needed, which is evidenced by the fact that he has gone the distance just once in 21 pro bouts.

"With Povetkin, I'm completely focused but also focused on having a good scrap, and don't mind coming away with a black eye and a cut nose because I want to give a bit to take a bit,"Joshua said. "Hopefully I take him down in round 8!"

Prediction

With knockouts in eight of his last 10 victories, including many against world-class level competition, it's hard not to consider Povetkin the toughest challenge Joshua has ever faced on paper outside of Klitschko. Povetkin's amateur background and experience only support said notion.

Yet the drawbacks against Povetkin's changes need to be considered just the same and are likely a main reason why oddsmakers have made Joshua such a huge favorite. Not only is Povetkin pushing 40, he will yield both a four-inch height and eight-inch reach advantage to Joshua, which could command similar logistical issues Povetkin faced against Klitschko.

There's also the question of whether Povetkin's reign of terror following the Klitschko loss, which featured five straight devastating knockouts, was fueled exclusively by PEDs. Not in Povetkin's favor is the fact that his next two bouts saw him claim decision wins for the first time in five years. Meanwhile, in his most recent fight, Povetkin was dropped in Round 2 by journeyman David Price before he rallied to finish the weak-chinned giant.

For Povetkin to have success, he'll need to work exclusively on the inside and look to rough Joshua up at every turn, even if it means bending the rules a bit. Not only will Joshua's jab be key in establishing distance but look for Joshua's sneaky right uppercut -- which he used to nearly behead Klitschko shortly before stopping him -- to discipline Povetkin from recklessly charging ahead.

This will create quite the dilemma for Povetkin in terms of how aggressive he is willing to be in order to get close while toeing the line of getting floored by heavy counterpunching.

Considering his advantages in terms of experience and taking fights deep into the later rounds, Povetkin's best shot at eventually getting to Joshua's often vulnerable chin might actually be in waiting him out a bit and hoping consistent pressure begins to gas the young champion.

Although Joshua has been seemingly focused on trimming bulk just a bit -- the 242 pounds he weighed in against Parker was 12 fewer than the Carlos Takam fight five months prior -- his muscular, 6-foot-6 frame hasn't been the most conducive to the 12-round distance and has caused him notable stamina dumps in the past, including the knockdown he suffered against Klitschko in Round 6.

Still, outside of exposing a Joshua vulnerability to pull the upset, the fact that Povetkin faces disadvantages in age, height, reach, speed and power don't necessarily add up to a formula for success. And say what you will about the lack of entertainment from Joshua's last two fights, the British star has continued to add smart wrinkles to his game which can only aid in his preservation against big punchers in close fights.

Knowing his history and personality, Povetkin is going to want to find out fairly soon what Joshua's chin and backbone are made of. The combination of his puncher's chance and Joshua's history being rocked by lesser opponents should make for an entertaining watch but it also will open the door to Povetkin's exit.

Pick: Joshua via TKO5