She's one of the globe's best players but the world won't be able to watch Ada Hegerberg this summer for what is being described as the mother of all women's tournaments.
"I don't mean to beat a dead horse (what a weird saying) but why exactly is Hegerberg not playing with Norway? If Messi or Ronaldo opted to not play in a World Cup the world would know why not with clarity," asked Heather O'Reilly, who plays for North Carolina Courage, in a tweet which received 1, 200 likes after Norway's squad was announced for the forthcoming Women's World Cup with Hegerberg absent from the list.
"I would like to know as well," replied Alex Morgan, the American who is as ruthless in front of goal as her fellow striker Hegerberg and who, last month, was named in Time magazine's list of the world's 100 most influential people.
The 23-yera-old Hegerberg used to play for Norway, but she doesn't anymore. The gifted striker, who is a Ballon d'Or winner and owner of multiple Champions League titles, may never represent her country again.
Though even her contemporaries want to know her reasons for giving up the chance of playing on the biggest stage of all, Hegerberg has been unwilling to give a blow-by-blow account of why she is at odds with her country's federation
"If I start saying ... things are going to blow up everywhere," Hegerberg, who last played for her country in 2017, tells CNN Sport as way of explaining why she has never divulged the specific reasons for sacrificing her international career.
It is not about money, she says, revealing that she respects elite male players for the oodles they earn, but ensuring the young girls following her path have the same opportunities as aspiring young male footballers.
"I was really honest with the national team representative what I felt wasn't good enough. What my experience had been since youth with the national team," she says, speaking at her club's training ground in Lyon.
"I wanted it to be a relationship between me and them, so they could take the feedback and do something with it.
"I have no thoughts about giving that to all the people. I think it's a good way to deal with things, to be honest -- honesty is the right way for development. Now I've done my feedback, it's up to them to do what they want to do with it.
"I've never been trying to control the starting 11, or something internal to the group. This is a feeling that's based on my whole experience with the national team. It's not even up to me anymore. I've moved on in my career and my life. I was sharp in what I meant with them, I don't really have a reason to share that with anyone else.
"I've always respected men's footballers for what they earn. The gap is enormous, but at the same time you need to give young women and girls the same opportunity as the men. That's where we need to do the change.
"There are federations, there are clubs, there are men in high positions who have that responsibility to put the women in the right place and that's where I think, I feel, and I know, we have a long way to go."
The Norwegian Football Association didn't immediately respond to CNN's request for comment, but in 2017 the organization and Norway's players' association signed an agreement on equal pay in a deal thought to be the first of its kind in international football.
It was the weeks leading up to her decision to ultimately quit the national team which were the most difficult, Hegerberg explains. "When I took the decision it was like a weight off my shoulders," she says.
"I've done what I can do to make an impact and do the best to make things better. When that doesn't work you have to take a choice. Life is full of difficult choices to make.
"I'm quite clear in who I am and where I want to go and, in the end, it was a decision I was confident with."
Hegerberg is an outstanding talent. This weekend she and her Olympique Lyonnais Feminin team will aim to win a fourth successive Champions League title. Should they beat Barcelona in Budapest on Saturday, they will become the first team, male or female, to achieve such a feat.
Last season she scored 53 goals in 33 games, including a record-breaking number in a single Champions League campaign.
On the back of such prolific form, Hegerberg became the first female recipient of the Ballon d'Or last December -- a historic event which was, for that week at least, overshadowed by one of the co-hosts asking the Norwegian whether she could twerk.
But despite the controversy, talking about winning such a prestigious award gives the player "goosebumps."
Though goals have not been as plentiful this season, she has still found the back of the net 26 times in a season where her club has continued its domination of French football.
The Norwegian moved to France in 2014, joining a club she describes as the model for how others should be organized. The team won its fifth league title this month, and the Women's French Cup. Since 2004, Lyonnais Feminin has secured 12 league titles and the Champions League five times. Arguably, this is the greatest women's team ever assembled.
Hegerberg credits the club's president, Jean-Michel Aulas, for investing heavily in the women's team, bringing in world talents such as Hegerberg and Germany captain Dzsenifer Marozsan, to name but two.
"You can have as much good players as you want but, at the end of the day, you have to work hard," she explains.
"It's a mix of everything. The fact of keeping a lot of players together for a lot of years so we get to know each other -- and know each other well on the pitch which is really important. We have the conditions to be the best, we have equality here because of one man basically, the president.
"I was [made to feel] welcome from day one when I came to Lyon. People think there are so many tough environments in this club but it's the opposite and you need that good atmosphere to succeed.
"We're so well integrated into the men's club, it's our club now -- men's and women's team. I'm really good friends with a lot of people who work in the club, outside the team, so just the fact that you eat together with the groundsman, the security man, the chef, for me is pleasant.
"It's something you should appreciate, and I appreciate a lot. That's what makes me feel so at home here as well.
"Lyon has the perfect model of how you should run a modern club. That didn't come by one year, investment in something good takes time. Give the women and the girls the same opportunity to do their sports is the best way to succeed. That's what I've been saying for a lot of years now, but it won't change by itself, you need to push for it."
Hegerberg grew up in rural Norway to parents who loved football so much that she jokes of being discouraged to take up handball and pushed towards the beautiful game instead.
Her mother, whom she describes as an "idol," and father made sure their three children, a son and two daughters, knew equality was important. They would discuss the subject at home. "There was never a question in our family, you play football whether you're a girl or a boy," she says.
"Just by coming from a family who talks a lot about that subject gave me the regard to look upon things. It's important to be conscious about these things, especially the youth so the future knows this is what it's all about."
Her elder sister, Andrine, whom Hegerberg also describes as a hero for forcing her to practice even when staying indoors was more appealing, plays in midfield for Paris Saint-Germain and will also not be playing for Norway in France next summer.
"We live in a world where equality is the most important thing. We're in 2019. Women must have their spots, and that's in society," says Hegerberg.
"That's why, even though there are changes, that's why you need to push for those changes every single day, never stop demanding for equality and development. That's why our position is important. Every player needs to use their voice to shake up things."
Hegerberg's willingness to sacrifice her own career in the hope that it will benefit future generations helps to partly explain how she has managed to maintain unprecedented levels of success, both individually and with Lyon.
It is, she says, "tricky" to stay hungry and motivated. But staying in her comfort zone, she says, would not only be detrimental to her game, but to women's football in general.
"I always look at what we can do better, what can the players do better, and that is obviously to train, train hard enough, stay out of the comfort zone and always increase the level. But, at some point, you need help to develop the product in the form of an investment," she says.
Working with a mental coach in Norway after every season, analyzing her campaign with her family and fiancé has also helped Hegerberg remain focused.
"It's important to think about what you've done and what needs to be done," she explains. "That's a clear plan I've had from youth. I always analyze myself."
As the world's best female players gather in France next month for the 2019 World Cup, when Hegerberg reflects on another season full of goals and trophies, and potentially more history-making feats, she will have no regrets.
"That's part of the consequence," she says of missing a tournament where the semifinals and finals are being held in a city she now calls home.
"I knew about the choice like this, but it doesn't stop me from making that choice because I believe in it so passionately because I want the best for the sport, I want the best for the youth, the ones who comes after. It sounds like a cliche but that's the truth."
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