Kelli Masters never planned on rocking the world of NFL agents, but she managed to do it anyway.

“I did not grow up wanting to be Jerry Maguire,” the 46-year-old sports agent tells Money. “That movie came out when I was in law school, and I remember how many of my classmates said, ‘That’s what I want to do.’”

She might not literally be shouting “show me the money,” but Masters has ascended to an enviable role in her profession. She’s represented massive deals in the NFL, including signing first-round draft pick (and No. 3 overall) Gerald McCoy to the Tampa Bay Buccaneers in a $63 million contract in 2010 — the first time a woman had gotten that far.

“I’ll tell you this: As an entrepreneur, it’s great when you make your first dollar,” Masters says. “That was my first dollar.”

How Masters found her calling — and climbed the ranks

Becoming an NFL agent is almost certainly much more laborious, complex, and expensive than it seems. You don’t simply walk into the job with swagger and a love of Any Given Sunday. First, you need to have a law degree — as Masters does — or other graduate degree. Then you have to pay a $2,500 fee to apply through the NFL Players Association, and if you pass the certification exam given once a year, you must become licensed in any state where you recruit and convince an agency or players themselves that you’re worth their time.

“So there’s a lot of pressure,” Masters laughs now as she looks back.

After law school, the Oklahoma-born agent, who’s still based in the state, became a partner-track lawyer at a law firm. Not feeling especially inspired, she dabbled in work with nonprofits on the side. That gave her the opportunity to provide legal expertise to an NFL player with a foundation. Suddenly, Masters was shifting to a new career path.

“I just knew I had found my calling in life, and that was at age 32,” she says.

With permission from her firm, Masters went through the process of getting certified and starting an agency while continuing her regular job. She had already decided she wanted to start her own business rather than join one of the major agencies, where at the time women were often sidelined in marketing and client services rather than overseeing contracts.

“It was probably the most impossible task I could’ve chosen,” she recalls. At the time, she thought maybe she could recruit clients by standing outside locker rooms. “People say, ‘What’s it like to be a woman in the NFL?’ and I say, ‘It’s tough, but it’s tough for any agent,’” especially those who strike out on their own.

But out of the gate, she gained the trust of Cody Hodges, the former Texas Tech University quarterback. While he went undrafted in the 2006 NFL draft they worked through together, Hodges ultimately got signed to the Tennessee Titans. The experience, Masters says, opened her up to contacts among teams that would end up being crucial to her success.

“I explained to him, ‘Look, I don’t really know what I’m doing. I’m learning as I go. I’ve never had a client in the NFL,’ and he looked at me and said, ‘Well, I’ve never had an agent. Let’s learn this together.’”

Having to explain that yes, ‘I really am the actual agent.’

There’s no getting around the fact that the NFL, perhaps even more than other major-league sports, is teeming with testosterone. Masters sought out advice from another female agent while starting out and has, at this point, “lost count of young women I’ve mentored.” Along the way, she’s made a point to celebrate them, toasting their success at events she hosts.

But part of being a pioneer has meant dealing with people who question her credentials purely because of her gender.

“Initially with players because it was so unheard of to be a woman NFL agent, I would walk into a meeting and players would be surprised or they would think I was maybe an assistant,” Masters says. “Nothing against assistants. I really am the actual agent!”

Most of the pushback, however, came from other agents. She remembers one particularly ugly run-in with a still well-known male agent at a combine.

“He walked up to me and started lecturing me on why women didn’t belong in the industry. He told me players would never respect me, that coaches, general managers, scouts wouldn’t listen to me,” Masters says.

“I stopped him and said, ‘You don’t know me. You don’t know why I’m here. I have a passion for this. I’m going to be successful whether you think so or not, and I won’t be the only woman.’ Fortunately, I proved him wrong.”

Proving that — and launching her career — came with the signing of McCoy. Though she didn’t fully appreciate that in the moment.

“I didn’t think about it being a history-making moment. No one then knew except for people in the industry,” Masters recalls. “When I went back to look at my phone, I had hundreds of messages from general managers and other agents just saying, ‘This is so amazing.’”

Fighting for every dollar: ‘You’re looking for every possible leverage a player could have’

Masters is hired, like all sports agents, to make money for athletes. She’s learned a lot about that — as well as about how to get some for herself. She spent years keeping her law firm job and not drawing any check from her new work, which doesn’t pay unless your client makes a team’s roster.

“I remember hearing about entrepreneurs going for years without making money,” Masters says. “Everything I made went straight into building the agency.”

Now KMM Sports has 33 clients across different sports listed on its website and says it has negotiated in excess of $120 million for clients through contracts, endorsements, and settlements.

But that transition period taught her one difficult lesson.

“I finally got smart about: What money am I investing, and what’s the potential return? I had to get to a point where I improved my ability to project that,” she continues. “I know I need to get on a plane to see my players face-to-face, and that’s important. But is it worth me spending the money to do that? I have to justify that money coming out of my pocket, justify every expense.”

Luckily, the money is now flowing more steadily. While she notes that a common misconception is that she manages her players’ money (actually, financial experts do that), using her legal know-how and experience, she’s fought to get every dollar for them in their contracts. Which, of course, means a nice cut for her. (How big that cut is varies, but NFL agents usually take a commission on contracts ranging from 1.5% to 3%, the maximum allowed in the league.)

“It’s really understanding the market for that player,” Masters explains. That includes using all the resources at her disposal — for instance, as an NFL agent, she’s able to look at every contract made in the league.

She also notes that it’s critical to understand where there’s room for advantage, like the amount of guaranteed money, payment schedule, or whether a particular city is amenable in terms of taxes and marketing. “If you do your homework, there’s very little that’s unknown. You’re looking for every possible leverage a player could have.”

She recalls working with Washington Redskins punter Tress Way through getting him on the team. While not the biggest contract she’s done, it was “life-changing” for Way. And if the moment wasn’t quite out of a Tom Cruise movie, it was still plenty memorable.

“He just wanted me to take the offer. He was scared. He’d been through a couple years trying to make a team, and he didn’t want to come off as ungrateful by rejecting. I said, ‘No, this is the process. This is why you have me — to negotiate for you,’” Masters says.

“I pushed back, and when I finally called him with the final numbers we agreed on, he was just overwhelmed with emotion. He had to sit down and take it all in. I’ll never forget that.”