NJ/NY Gotham FC and Republic of Ireland midfielder Sinead Farrelly announced her abrupt retirement from soccer on Friday due to post-concussive syndrome, which will require rehabilitation.

Gotham FC said in a statement that Farrelly "was advised by a neurologist to cease playing soccer due to the cumulative head injuries that she has sustained throughout her career, leaving her vulnerable to additional head injuries if she were to continue to play."

Farrelly, 34, became one of the catalysts of the National Women's Soccer League's recent off-field reform after she went public with her story of alleged sexual coercion by former coach Paul Riley. Farrelly returned to the league in 2023, after initially retiring in 2016, and she helped Gotham FC win its first NWSL title in November.

"Thank you to Gotham FC and all its staff, my teammates, my family, my people and the fans who kept me on this path when I wanted to turn and run," Farrelly said in a statement.

"I'd be nowhere without you all. I promise this ending is a gift, a blessing and just the beginning of something new. I am so grateful that this insane chapter even existed at all, let alone end in such a way where I am feeling so fulfilled and at peace. This truly has been so special."

Farrelly joined Gotham last preseason as a non-roster invitee. She earned a roster spot and signed a contract in March 2023, and she earned a call-up to Ireland for her first international caps a month later. She was named to Ireland's 2023 World Cup roster and started all three games for the team at the tournament, which was Ireland's first.

In November, Farrelly came off the bench for Gotham to help the team secure the NWSL Championship in a 2-1 win over OL Reign (now Seattle Reign FC). She made only one appearance this season.

Mana Shim was Farrelly's teammate with Gotham last year. Shim spoke up alongside Farrelly in 2021 to challenge the league's previous mishandling of Riley. The players alleged that their stories -- including Shim's allegations of sexual misconduct from Riley -- were not taken seriously when they reported them to the Portland Thorns and the NWSL in 2014, nor when they raised concerns to new leadership earlier in 2021.

Riley continued coaching in the league after leaving Portland following his contract ending after the 2015 NWSL season. He went on to win three NWSL championships before being fired by the North Carolina Courage the same day The Athletic's story was published.

Both Farrelly and Shim returned to the NWSL, and Gotham FC, last year; Shim had not played in the NWSL since June 2018.

The league they returned to was one that had just gone through a long reckoning sparked by the public sharing of their stories. Two, year-long investigations, including one led by former U.S. deputy attorney general Sally Yates, throughout 2022 revealed systemic abuse within the NWSL. The investigations led to lifetime bans from the league of four coaches, including Riley, and several other suspensions. It also forced the sale of the Portland Thorns to new ownership, a deal that was completed in January.

"On a personal level, standing on the field with Mana and Sinead and seeing them win the championship, that was like a full-circle moment that I never imagined could have happened -- ever, putting aside that it was a year later," NWSL commissioner Jessica Berman recently told ESPN. "But that they'd actually be back and win a championship and feel so good about the league. I feel really proud of that on our collective behalf."

Farrelly made 18 appearances for Gotham in 2023, starting in seven of them. She registered one assist. She previously played for the now-defunct FC Kansas City in 2013, the league's inaugural season, before playing for the Thorns in 2014 and 2015.

She appeared in all three playoff matches for Gotham in the team's run to a 2023 title.

"Sinead is truly an exceptional person and we are incredibly grateful to be a part of her journey," Gotham FC general manager and head of soccer operations Yael Averbuch West said in a statement. "It has been one of the greatest honors of my time at Gotham that Sinead chose our club to make her comeback. We are happy to support her and very excited to see her next chapter."