WWE Superstar Roman Reigns shares how he is feeling after being a part of WWE SummerSlam's main event and compares the matchup to his earlier years of playing football. (2:23)

It's the morning after a physically grueling SummerSlam main event against three of the most athletic giants in WWE history, in Brooklyn's Barclays Center, but Roman Reigns (real name Joe Anoa'i) is up bright and early. He hops into a blacked-out SUV and takes a 40-minute trip from the Holiday Inn in downtown Brooklyn to the Upper West Side of Manhattan to make an appearance on SportsCenter.

His body is feeling the toll of having been tossed around, punched and choked out by the likes of Brock Lesnar, Samoa Joe and Braun Strowman in what was easily one of Reigns' best and most physical matches since his WWE debut in 2012. As far as intensely physical matches go in the last few months in WWE, no one can hold a candle to the absolute wars between Reigns and Strowman. They've been over the top, to be sure, involving two destroyed ambulances, but each match has involved intense, physically grueling moments that have come to define the WWE's rivalry of the year.

Roman Reigns has spent the better part of the last year battling with Samoa Joe and Braun Strowman, putting on intensely physical matches on an almost nightly basis. Anthony Geathers for ESPN

That's not to say that anything can prepare you for the kind of force a combined 1,200 pounds of competitors can generate, as was the case at SummerSlam, but it's the way things have played out of late for Reigns.

"I hate to say it's the norm, but it feels that way," said Reigns, as he settles into his chair. "I don't know if it's a good thing or a bad thing, but I've been kind of used to running into these big redwood trees."

The other norm for Reigns is the reaction he gets almost every time he appears on WWE Raw or WWE pay-per-view. Every time Reigns' music hits, he's welcomed by a chorus of boos, driven largely by the adult male portion of the crowd. It reached a fever pitch the night after WrestleMania, when the entire opening segment of Raw was based around the crowd getting so loud that Reigns had to wait to speak. It went on for 10 minutes. It hasn't quite reached that level since, but that atmosphere has become a constant presence when Reigns is in the ring.

His merchandise is still among the most popular in the WWE -- you need only look at any WWE event crowd to see the evidence -- and a significant, if less audible, portion of the crowd is still behind him, so do the boos mean Reigns is the bad guy?

"To me, I'm neither," said Reigns on whether his role is as a babyface or a heel. "If I'm totally off here, then I'm totally off, but I'm the first of my type. I'm the first true gray area guy ... just being what he was born to be."

Reigns has made similar points on air, declaring, "I'm not a bad guy, I'm not a good guy -- I'm the guy." Paul "Triple H" Levesque -- the executive vice president of talent, live events and creative for WWE, and an in-ring legend in his own right -- echoes those sentiments.

"Fans will say that all the time -- 'I hate Roman Reigns,'" said Levesque. "They did it with [John] Cena, too. I remember telling Cena years ago, when it started happening to him, 'Dude, what do you care? You're the Yankees and the Red Sox at the same time.' The place is sold out.

"When people say, 'They should just turn Roman,' why?" said Levesque. "For the people that hate him, he's already turned, and for the people that love him, they don't want him to turn. And if we turned him, the people who hate him would switch to loving him, and the people who love him would switch to hating him."

In some respect, Reigns does share certain similarities with John Cena, a traditional good guy whom some fans have turned against because of any number of perceived slights to their own favorite superstars, or because of heavy-handed attempts to position Cena or Reigns as the undeniable No. 1 good guy ... fan reaction be damned. At the end of the day, it still puts butts in seats.

"Roman Reigns sells tickets. Roman Reigns sells merchandise. Roman Reigns is one of the most looked-up guys on the internet," said Levesque. "He's all of these things. It doesn't matter. We're in a world now where there's so much access to everything that you can't dictate to somebody anymore.

"That's what the internet does -- it allows you to have your own opinion, and you can find somebody that backs your opinion up so you're not all alone," continued Levesque. "You can hate who you want to hate, love who you want to love, and no matter what we [the WWE] do, no matter what it seems like we're promotionally getting behind, it really sort of doesn't matter. We can't control that."

They're similarly major draws, but the similarities don't seem to carry much beyond both of them being booed by a similar segment of the audience. While Cena will occasionally joke with the crowd and direct fans as they sing "John Cena sucks" in time to his entrance theme, he almost always reverts to a traditional good-guy role when the dice are down.

But Reigns, after an adjustment period, has rolled into the reactions he gets and made it a part of his character and motivation.

Roman Reigns and Brock Lesnar seemingly have some unfinished business, but with Lesnar pinning him in the center of the ring at SummerSlam, it may take some time for them to come back together. Anthony Geathers for ESPN

"I don't go out there and act crazy and flail around and be a heel. I don't come out there smiling and kissing babies, telling each town it's my favorite town at the end of the night," said Reigns. "I keep it real. Sometimes I'm in a good mood. Sometimes I'm in a bad one. I want my character to be as human as possible, but not just a regular human that you see every single day."

In Reigns' eyes, it's been an opportunity to prove his versatility. Because the crowd is already split, no matter who he's in the ring with, he can adapt to each scenario in a different way.

"It's just one of those things that helps me work with everybody. It's not about, 'Well, we can't tell this story because it's two bad guys going against each other, or it's two good guys.' I can adjust to any way [we want to do it]," said Reigns. "I can wrestle any way I want. Sometimes you fight pissed off. Sometimes you fight smart with technique. It just depends."

As far as the particularly vociferous crowds that tend to come out for major pay-per-views, and the shows in the days that follow, Reigns has a good sense of what's coming before he makes his entrance.

"I get excited no matter what, because it's a different crowd every time for me," said Reigns. "Now that I've been able to make my rounds a few years now and be to each market several times, I have a better understanding. That's what makes a performer smarter ... the experience of knowing each region, knowing the fan base that's at the actual show, knowing how they sound.

"If you just sit back and listen to each reaction, you can really tell what's out there. You can hear the kids. You can hear the women. You can hear the grown men."

A Shield reunion?

Considering the reactions he's received of late, it might be hard for some fans to remember how heartily Reigns was cheered for the bulk of his run as part of The Shield. Alongside Seth Rollins and Dean Ambrose, Reigns charged into the very same Barclays Center in December 2012 for The Shield's in-ring debut.

"That's where my career started, essentially," said Reigns. "Our first match ever, when we broke in as The Shield, was in the Barclays in a TLC match against Team Hell No and Ryback."

The Shield spent the better part of two years as one of the hottest groups in recent WWE history, and with the recent reunion of Rollins and Ambrose as the new Raw tag team champions, the looming question has to be whether Reigns will get involved at some point too, making it a full Shield reunion

"Over the next few weeks, we'll be able to see it play out," said Reigns. "But the main thing right now is I've been in the title picture for the Raw brand, so I can firmly say neither of those guys would leave [that opportunity] to rejoin The Shield [and] rekindle that flame."

With the effort that was put into making the Ambrose-Rollins journey to the tag team titles make sense, it hardly seems fitting to force anything too quickly with Reigns. Since SummerSlam, Reigns has also been on a collision course with Cena, with a match already set for WWE No Mercy in late September.

If The Shield finally comes back together, the moment should be well-earned.

Where Reigns gets his inspiration "Watching different movies, different stories, different threads that you can take," said Reigns, "Different emotions, different demeanors and mannerisms. 'Game of Thrones' is a great one. Just different dialogues and communication, things like that. Those are the type of ideas that I try to pull from. "Ricky 'The Dragon' Steamboat taught me a long time ago. He's one of the best sell jobs of all time. To this day, I still try to look to his selling and little things that he does to make it feel real -- the facial [expressions], the way he'll target a kid in the crowd and wince at him. "He said he was watching 'Raging Bull' with Robert De Niro. He just told me, 'If you ever get a chance, watch that movie. The way De Niro sells in those boxing matches is just incredible.' "From there, [Ricky] just had a whole new identity of how he wanted to put over the physicality of what we do -- the storytelling of good versus evil. The good being down, and digging deep, and fighting back to overcome the adversity. I'm not quite there, to be like The Dragon. But hopefully one day, [at some point in] my career, I'll figure out how to get there."

"Maybe I'm a third wheel at this point," said Reigns. "It just really depends. I feel like the next few weeks are really going to play out some important things for me. Obviously, I need to transition coming out of this big feud between the four monsters."

The way the crowds are reacting to all three former members of The Shield these days, the money may be on revisiting their conflict. They've had plenty of one-on-one showdowns between the three of them, but only twice -- in a Fatal 4-Way (which also featured Randy Orton) at Payback 2015 and a triple threat match at Battleground 2016 -- have they all been in the ring at the same time with a world title on the line.

It has all the makings of a match that deserves a stage like WrestleMania.

"I can go with either of the guys, my Shield brothers. Me, Dean, Seth, we can go in there and tear it up, counter, because we know each other so well," said Reigns. "Just completely tell a different story. Maybe a little bit faster-paced, maybe a little more emotional, because we have so much baggage there through our characters."

Just as he feels his character gives him a certain versatility to take on superstars all over the spectrum of good and evil, Reigns also points to his physical stature as an asset against almost everyone the WWE can line up in front of him. Whether he's bumping around for Lesnar or Strowman, or tossing AJ Styles across the ring, each match offers a different opportunity to tell a unique story.

"For me, it's just a learning experience," said Reigns. "I like it different, because I feel like that's what really made me progress in such a short amount of time. I mean, I think I've been on the road now for five years coming up, about three of them in a singles capacity. When you get thrown in the fire like that, considering I've only been wrestling since 2010 -- granted, I'm from a wrestling family and I've been around it -- it's a whole other beast being in the ring."

Still learning

Despite a mercurial reaction from live event crowds, Roman Reigns has had some of the best matches of his career against Braun Strowman. Anthony Geathers for ESPN

Despite ring attire that's similar to what he debuted in, and a Shield-reminiscent theme, Reigns has indeed changed a lot over the course of his career. A lot of that has to do with just how quickly he was expected to progress. He was around wrestling most of his life, to be sure, as the son of Sika, one-half of the Wild Samoans, and a part of the greater Anoa'i family. But first and foremost, Reigns' athletic background was in football.

Just two-and-a-half years after signing a WWE developmental contract in 2010, he was making his WWE in-ring debut. His life and career have forced a constant evolution upon Reigns, requiring him to soak up inspiration and knowledge from many different sources.

"Early in my career, I looked towards veteran wrestlers or people before me and tried to tap into that," said Reigns. "Not necessarily their mannerisms or how they carried themselves, but just the way they conducted their matches and the psychology and why they were doing stuff. Why they would take their times here, why they would flurry here, why they would pander to the crowd here. There's just different little things that I needed to look at.

"At this point in my career, it's hard for me to watch some of my stuff," said Reigns. "It kind of always has been. Early on, I would watch my stuff and I would learn from it, treat it like football tape. Watch my footwork, watch my mannerisms, looking at my shoulders and how I was carrying myself."

Now, with a firm command of who he thinks Roman Reigns should be, it's more about picking up nuances from unexpected places.

"I just try and tap into other things, like real life mannerisms. I get them from my kids, different emotions. Sometimes when you're playing with your kids and they get pissed, you can see a true anger emotion that's not convoluted with any other reasoning," said Reigns. "They're just mad. They know they're mad and they're going to show you they're mad."

In the last couple of weeks, Reigns has been put on a collision course with John Cena. Despite receiving similarly mixed reaction from live crowds, their personalities make them natural adversaries. Anthony Geathers for ESPN

While some fans look cynically at Reigns and point to him as an example of "too much, too soon", in terms of his push towards the top of the WWE, his connection with the audience is undeniable, good or bad.

Having waded his way through some rough waters, Reigns knows what it takes to be a top superstar in the WWE, and how to deal with hostile crowds. As far as the up-and-coming generation of WWE superstars goes, Reigns suggests that it's simply about throwing every ounce of yourself into whatever opportunity presents itself.

"Guys like Big Cass... like Baron Corbin, different guys that are new," said Reigns. "Jinder [Mahal] is another one. They're getting these opportunities, and it's important that they run with the ball and they don't look back, because you drop that ball you may never get it again.

"For me, learning every single night by being thrown in the fire, sink or swim -- that's what made me the performer I am today."