Developmental line judge Sarah Thomas, left, makes a call during the first half of a preseason NFL football game between the Seattle Seahawks and the San Diego Chargers on Aug. 15, 2014, in Seattle. (Stephen Brashear/AP)

Before every kickoff, football referee Sarah Thomas looks in the mirror and tucks her hair into her cap.

Most athletes have a pregame ritual, and this is hers. Once on the field, it makes her practically indistinguishable from the rest of the otherwise all-male crew, just another black-and-white striped shirt and authoritative bellow. Often, the players and coaches don’t even notice she’s a woman until they give her a close look. And in a good game, when the score is tight and Thomas is making all the right calls, no one has time to give her a close look.

That’s the way Thomas likes it.

“When you’re out there officiating, the guys don’t think of me as a female. I mean, they want me to be just like them — just be an official — and that’s what I’ve always set out to do,” she said Wednesday.

Starting this fall, Thomas will be tucking her hair into a cap with the NFL logo on it. The league named her Wednesday as one of nine new referees hired for the upcoming season — making her the first full-time female official in its 95-year history.

The announcement brought a flurry of celebration and, inevitably, some cynicism. Mike Florio, creator of NBC’s “Pro Football Talk,” wondered whether Thomas’s hiring is an attempt to address the league’s recent bad press — especially a video that surfaced last fall showing Baltimore Ravens running back Ray Rice punching his then-fiancee.

“It’s fair to at least wonder whether a desire to undo the considerable damage done to [the NFL] due to the bungling of the Ray Rice case and a longstanding lack of sensitivity to domestic violence influenced the process that resulted in the hiring of Sarah Thomas,” he wrote in a blog post. The league “needs to be prepared to treat Sarah Thomas exactly the same way any other official would be treated,” he added.

But Thomas is hardly an untested neophyte, plucked from obscurity for a PR stunt. She’s been officiating since 1996, when, for the first time since she’d learned to walk, Thomas found herself without a sport to play.

The Mississippian had been a high school softball star and a college basketball academic all-American. After graduating from the University of Mobile in Alabama, she played in a men’s basketball church league until a pastor voted her out.

So when her brother, Lea Bailey, invited her along to a meeting for football officials, she was intrigued.

“I said, ‘Can girls do that?'” she told USA Today last year. “Lea said, ‘I guess so.’”

He warned her that the meeting comprised “a bunch of old men sitting there” and that she might get some stares. But Thomas was undeterred. She soon became the first woman to officiate for the Gulf Coast Football Officials Association, which oversees high school games.

It wouldn’t be the last time Thomas found herself the only woman on a field dominated by men. About a decade later, she was picked as the first female referee for a major college football game. She was the first woman to officiate at a Bowl game, the first to referee in a Big Ten stadium.

[NFL announces hiring of Sarah Thomas as first full-time female official]

Thomas, who has two brothers, told Mobile’s Press-Register in 2009 that she grew up accustomed to being the only girl.

“I always just played with the boys,” she said.

As an official, Thomas quickly felt at home on a football field, though players and coaches were sometimes startled to see a woman’s face beneath her black cap. She only ever felt awkward during her pregnancies (Thomas is married and has two sons and a daughter), when she worked the clock wearing a maternity version of an official’s shirt sewn by the spouses of her crew.

“Standing out there, big and in stripes has been the only time I’ve ever felt out of place,” she told the New York Times in 2009.

Sarah Thomas stretches in the officials’ locker room before the start of a college football game in Memphis in 2009. (Mark Humphrey/AP)

Thomas worked as a pharmaceuticals sales rep throughout her years overseeing youth league and high school games, and by 2006 she was considering hanging up her whistle to focus on her career. Her sons were getting older, and she had already worked high-school playoffs and all-star games — she figured she had made it as far as she was ever going to get as a referee, according to the Associated Press.

But then she got a call from Gerald Austin, a former NFL ref who oversaw officials for Conference USA, the college sports subdivision. He wanted her to come to program’s training camp in Reno, Nev.

“She made one tough call after another and nailed every one of them,” he told the New York Times in 2009. “There was no reason not to hire her.”

The day after Thomas’s hiring was announced, Austin received four applications from other women for spots on his staff. It was the first time any women had applied to referee for him, he told the Associated Press in 2007.

The following year she was picked to work a game between University of Memphis and Jacksonville State. At the time, it was most high-profile college football game to be officiated by a woman.

“I think it’s like any other time you are the first one,” Austin said at the time in 2007. “If she does a good job, I think she will have a very positive effect. If she messes up, some people might say females aren’t ready.”

Thomas did not mess up.

Sarah Thomas works an NCAA college football game in Memphis in 2009. (Mark Humphrey/AP)

By 2009, she had a crew and a full slate of 11 games a season. She was starting to get noticed by other officials and NFL scouts, and by reporters — who always comment on her habit of hiding her bun beneath her hat.

“I look like a boy,” she told an Associated Press reporter before a game in Memphis.

“Actually, she looks like a referee,” the reporter noted.

Once on the field, Thomas had the appearance and the authority of any one else wearing the black-and-white striped ref’s uniform. Her ability to blend in is one of the qualities that makes her such a good official, sports writer Rick Cleveland said.

“If you notice officials, it usually means they’re not doing their job correctly. And I can’t remember a time that I’ve seen a game that she officiated when I noticed her,” he told NPR.

Cleveland, who is also executive director of the Mississippi Sports Hall of Fame, said he has no doubt Thomas belongs in professional football.

“Football is thought of as probably the most, quote, ‘manly’ of sports. But it’s like [long-time NFL official] Jack Vaughn told me a long time ago, you don’t have to be a man to tell whether somebody jumped offsides or not. And you don’t have to be a man to learn the rules of football.”

Not everyone responded that way. It didn’t take long after the news of Thomas’ hiring for the Internet to erupt with sexist skepticism.

Jacksonville Jaguars defensive tackle Sen’Derrick Marks speculated in an interview with TMZ that Thomas’s hiring was a publicity stunt “like the Michael Sam situation.”

“If he wasn’t gay, he would have gone undrafted,’’ Marks said of the defensive end, who was a seventh-round draft pick last year but failed to make an opening-season roster. “Instead, the league drafts him because I think they are trying to monopolize every aspect of the world. The same thing with a female ref. … For the league, it’s great publicity. The NFL is all about monopolizing every opportunity.’’

Later Marks added, “I hope it works out for her.”

In a press call Wednesday, NFL Vice President of Officiating Dean Blandino pushed back against claims that Thomas’s hiring was a response to Ray Rice or any other scandal. He explained that Thomas has been in the league’s referee development program for two years.

“We feel she’s ready to come into the league,” he said. “Regardless of everything else that’s happening.”

In the same call, Thomas brushed off the notion that her treatment has been anything but professional. It’s a stance she’s maintained throughout her career.

“I’m going at it the same way they’re going at it. There’s a job to be done. It just so happens I’m a female,” Thomas told the AP in 2009. “… My goal is to just be the best I can be every time I’m given the opportunity to work. I know it sounds so cliche, but it’s just the mindset of officials.”

Which is now exactly what she is.

In this June 12, 2014, file photo, Sarah Thomas, right, walks off the field after a Cleveland Browns mandatory minicamp practice at the NFL football team’s facility in Berea, Ohio. (Mark Duncan/AP)