In perhaps the biggest international signing of National Women's Soccer League history, French midfielder Amandine Henry has agreed to join the Portland Thorns, according to sources.

Henry, widely considered one of the best players in the world, will leave two-time European champion Olympique Lyon when her contract ends this summer, according to sources who spoke on the condition of anonymity because the deal has not yet been formally announced. A spokesman for the Thorns declined to comment.

Henry, 26, represents a major signing for both Portland and the NWSL. She received the Silver Ball at the Women's World Cup last summer as the second-best player of the tournament behind American Carli Lloyd. Last year, Henry was named the second-best player in Europe behind Germany's Célia Šašić and was on FIFA's shortlist for World Player of the Year.

The team was close to signing a player that was deemed out of reach in early negotiations, Thorns head coach Mark Parsons said in a phone interview last month. He declined at the time to confirm whether the player he was referring to was Henry, but now it appears that was the case.

"The player that we're close with, we probably didn't even think it was possible and looked at other players first because they were more possible," he said. "And now we're very close with that player. If it comes off, I think this will be a very special thing for us."

Henry has been with Lyon since 2007 and has openly admitted she's ready to move on. During her time with Lyon, she has helped the club win multiple Champions League titles, Coupe de France titles and league titles.

The two-way midfielder was left off France's roster for the ongoing SheBelieves Cup hosted by U.S. Soccer -- she is still recovering from a minor calf injury.

Portland is no stranger to high-profile international signings. In 2014, goalkeeper Nadine Angerer signed with the club after being named FIFA's World Player of the Year. She retired after the 2015 season and joined the Thorns as a goalkeeper coach.

Signaling A Shift

As the NWSL loosens its limits on international players and slowly raises the per-team salary cap, the acquisition of Henry may signal a shift in the NWSL toward attracting big-name overseas talent, despite the league lacking the high six-figure salaries available in Europe.

"The United States is a notch above," Henry said in an interview last year with a French media outlet. "There, there's a true recognition, and one speaks of women's football as the first sport. It is a culture. It's true that experience would interest me."

The NWSL can hardly compete with the top European leagues in player salaries. Last year's team budget cap was just $265,000, to be divided among a 20-player roster, excluding U.S. and Canadian national team players.

Amandine Henry hopes to raise her stock when she joins the NWSL's Portland Thorns. Dennis Grombkowski/Bongarts/Getty Images

But the NWSL can raise a player's stock in a way other leagues around the world can't.

"We can't pay a wage that others can, but it does turn into money at some point," Parsons said in the phone interview, adding that Portland offered a "full package" beyond salary. "That recognition, that exposure -- it's raising a player's profile."

The league was perhaps initially established to fill in the American development gap between college-aged players and the U.S. women's national team. The U.S. Soccer-backed league started in 2013 with just two international roster spots per team, forcing clubs to draw from mostly American talent to fill rosters.

But the NWSL's American influence has increasingly made it attractive to players from other countries. With the USWNT continually atop FIFA's world rankings and fresh off winning the Women's World Cup, the NWSL can boast many of the best players in the world. U.S. Soccer requires its national team players to compete in the NWSL.

Women's soccer is more popular in the states than in the rest of the world, and the Portland Thorns attracted an average of about 15,600 fans per home game in 2015, thought to be the largest average attendance for a women's soccer team in the world.

Joining Henry in Portland will be Lindsey Horan, 21, who made the decision to leave Paris Saint-Germain because of her budding opportunities with the U.S. national team. She's the first American woman to go pro straight out of high school in 2012, when she chose to play in France.

The NWSL season begins on April 16 and will run through the end of September with a month-long break for the 2016 Olympics in Rio, where many internationals, including Henry, are expected to compete.