The National Women’s Soccer League (NWSL) and NWSL Players Associations are joining Project ACL, the global research project aimed at reducing anterior cruciate ligament (ACL) injuries in professional women’s football.
The initiative launched two years ago in England, with an initial focus on players in the Women’s Super League (WSL). On Tuesday, those behind the project gathered at Nike’s New York headquarters to officially launch the collaboration with the NWSL and NWSLPA.
“There’s been an increase in professionalization, an increase in expectation on our players and demands on the players and injuries like ACL (injuries) have not decreased,” said Alex Culvin, FIFPro’s director of women’s football. “That’s why we believe Project ACL is so critically important.”
Research suggests ACL injuries are two to six times more likely to occur in women than men, and about two-thirds of those injuries occur when there is no physical contact. Yet, there is little understanding on how to reduce these injuries in professional women’s soccer. Research, until now, has primarily focused on amateur players.
Project ACL was launched by FIFPro, the Professional Footballers Association, Nike and Leeds Beckett University in 2024. It focused on WSL players over a three-year period. The WSL edition, in its final year, was viewed as the project’s pilot. The hope, from the very beginning, was to expand this initiative globally, particularly with an eye to one day bring it to the NWSL.
“To have the two best leagues in global women’s football contributing to Project ACL is something that we feel incredibly proud of,” Culvin said, “and we are determined to make significant impact for the players through this project.”
So far this season, six NWSL players have been placed on the season-ending-injury list in 2026 after tearing their ACLs. Angel City’s Hina Sugita, Denver Summit’s Jasmine Aikey, Utah Royal’s 16-year-old KK Ream and Bay FC’s Alyssa Malonson were ruled out in March. Portland Thorns’ Bella Bixby and Chicago Stars’ Natalia Kuikka were ruled out in January during their preseasons.
“My hope and ambition is, really, that we don’t have as many ACL injuries happen in the game,” Tori Huster, a former NWSL player and the NWSLPA’s deputy executive director, said on Monday. “Over the course of the last two seasons, we have seen somewhere between 20 and 30 players sustain an ACL injury. Personally, (I) don’t want to see that anymore.”
FIFPro are the drivers behind Project ACL. The NWSL and NWSLPA will work closely with existing project partners to continue building an “evidence-informed” body of work to better understand ACL injuries. This will examine the physical causes of the injuries, as well as environments players train, compete and recover in.
The goal is to better understand the working environment, identify best practices and provide solutions to support the reduction of ACL injuries in the NWSL. The project will run for three years, beginning in June. Notably, this will be the first study of its kind that looks at professional women’s football across multiple leagues.
The project has so far surveyed multidisciplinary teams across 12 WSL clubs about available resources and injury-prevention strategies. Researchers have so far conducted interviews with more than 30 players about their experiences.
An example of progress includes tracking players’ workload, travel and “critical zone appearances,” or games with less than five days of recovery time. This data is spread across FIFPro’s Player Workload Monitoring tool, which helps assess potential links between player workload and subsequent injury. Soon, NWSL player data will be loaded into the database.
The NWSL expanded by two clubs to a 16-club format in 2026, which, of course, translates to more games this season. This has meant more mid-week matches, meaning players may have weeks where, for example, teams are playing three matches across eight days. The league is only growing, with expansion clubs in Atlanta and Columbus debuting in 2028.
That’s without considering the introduction of international competitions, both at the national team and club levels, as women’s football continues to expand.
“The more leagues (that are) a part of this, the better,” recently retired Crystal Dunn said during a player panel on Monday to help launch Project ACL. “We should be pushing for leagues to get behind this so that we support and protect the product that is on the field.
“Demand for us to play more games should never go away. We should be continuing to push for these opportunities for players have more visibility and to be able to play in multiple games. I think now it becomes, (a conversation about) ‘what does load management look like?’”
Jordan Angeli, a former NWSL-player-turned-broadcaster and Denver Summit co-founder, founded the ACL Club, which encourages athletes through their ACL recoveries. Her playing career was cut short by injury. She tore her ACL in her left knee three times in five years.
“More players are not just playing in the league, but they’re playing in the league longer,” Angeli said, hinting to potential changes that could stem from Project ACL. “Maybe this helps change with load management. Maybe there’s more players on a team because of the research, that we understand how women’s bodies work better.”
Merritt Mathias played 11 years in the NWSL before retiring at the end of the 2024 season. When she tore her ACL in 2019, the first question she remembered being asked was, “Are you on your period?” The correlation between a menstrual cycle and injury remains under-researched.
“There is such an opportunity to really shape how women professional athletes are treated within their environment, and that’s not to say you mitigate the risk of ever tearing your ACL but can we have understanding around this time of your cycle,” Mathias said. “Maybe you are going to eat differently, you are going to live differently, you are going to be set up in a way that, in the best way possible, we are starting to really understand and shape what it feels and looks like to be a women’s professional athlete in the NWSL.”