Frankie Edgar called Clint Wattenberg in late June with some questions. It was about two weeks before Edgar's scheduled bantamweight debut.

In more than a decade with the UFC, the former lightweight champion had never really cut weight before. He never needed to. Unlike most high-level MMA fighters, Edgar always walked around at or near his fighting weight.

Edgar didn't know what fight-week protocols were regarding dropping pounds, so he got on the phone with Wattenberg and asked the UFC Performance Institute director of sports nutrition the most basic questions.

"What's a water load?" Edgar asked.

Wattenberg found Edgar's questions "very humorous," but mostly refreshing. Water loading is the practice of drinking large volumes of water leading into the night before weigh-ins, then restricting water consumption and sweating out the fluids -- and final pounds -- in a sauna or bathtub. It's a common practice in MMA, but Edgar had never done it.

This week is a whole new world for the 38-year-old Edgar, who was the UFC champion at 155 pounds and a perennial contender at 145 pounds before making the decision to drop to 135 last summer. On Saturday, the future UFC Hall of Famer will fight Pedro Munhoz in the main event of UFC Fight Night in Las Vegas, a bout that was rescheduled from its initial July 11 date on Fight Island after Munhoz tested positive for COVID-19.

After 15 years as a pro, 32 career bouts and a long list of accomplishments, this will be the lightest Edgar has ever weighed in MMA.

He's just a blank slate," Wattenberg said. "Just like a young athlete asking all the right questions and being real eager to be steered in the right direction."

"Blank slate" and "legend" don't usually go together. But that's what's going on here. Edgar said he first got in touch with Wattenberg, a fellow former college wrestler, about 10 months ago when he finalized his decision to move down to bantamweight.

There wasn't much else for Edgar to do at lightweight or featherweight. At lightweight, he was the champion from 2010 to 2012. At featherweight, he had a five-fight winning streak and then another two-fight streak to set up title opportunities that ultimately resulted in losses. Edgar never has been big for his weight class, and the calls for him to move down in weight started almost a decade ago, when Edgar lost the 155-pound title.

"I know a lot of people question where I'm at in my career," Edgar said Wednesday during the UFC's virtual media day. "I'm a little older. Coming down a weight class, people were questioning my abilities here. I want to go out there and, moreso than prove to anyone else, I want to prove to myself that I'm still a top dog in whatever weight class I fight in."

Wattenberg started helping Edgar with his nutrition last year. That was temporarily put on hold when Edgar surprisingly took a short-notice featherweight bout with "The Korean Zombie," Chan Sung Jung, last December in Jung's home country of South Korea. Jung stopped Edgar by TKO in the first round.

That was Edgar's swan song at featherweight. After Edgar recovered from that defeat, Wattenberg worked with him weekly or biweekly on a nutrition plan. Before the move to bantamweight, Edgar basically ate whatever he wanted. A big part of getting Edgar down to 135 pounds, Wattenberg said, was changing not only what Edgar ate -- fewer calories -- but also when.

If a high-priority workout was on deck, Wattenberg told Edgar to eat things more rich in carbohydrates. If it was a lighter workout, Wattenberg said to cut the carbs and eat something with more fat.

We've been working on this quite long term with the idea of not shocking the system and just cutting a ton of weight," Wattenberg said, "but really working to get the body prepared and everything else."

Wattenberg's role at the UFC Performance Institute (PI) in Las Vegas is to help athletes with their nutrition, but sometimes that job includes fighters contacting him in order to get his assistance in making drastic weight cuts. That is not the case with Edgar, Wattenberg said.

Frankie has trained his body down so that he's able to do this as many times as he needs to," Wattenberg said. "That's one of the big issues that we see with athletes is they do crash it down, and they may successfully make weight once or twice or multiple times, pushing the limit. But over time, it has a metabolic impact, so it gets harder and harder. That's when we see these athletes maybe as their career develops and they start being up for bigger fights, they start missing weight. It's not necessarily that they did something wrong; it's an accumulation of the kind of trauma to their body.

"What I would say is that Frankie has done it in a way that I have no concerns with him doing this for another five years."

Does Edgar have another title run in him at a different weight class? That's the plan. Munhoz is ranked No. 7 by ESPN among MMA bantamweights. A victory Saturday would immediately put Edgar somewhere in that championship discussion.

"I've just gotta worry about winning my fight Saturday," Edgar said. "Winning has a way of taking care of things. And if I could do that, anything is possible. What I've done in my career, I'm always knocking on the door. I've always had opportunities presented to me. If it does come up, of course I jump at it."