Western Sydney Wanderers have landed a coup in signing United States forward Lynn Williams for the upcoming W-League season, sources have told ESPN.

ESPN understands that rival Australian side Melbourne City had also been engaged in talks with Williams to join the club from the beginning of the 2019-20 season but are now resigned to being comfortably outbid by Western Sydney.

Though she has never played in the W-League, Williams maintained her fitness by training with City during the 2018-19 W-League season and reports at one point declared that she was set to sign a guest player contract with the then defending W-League champions in the wake of an injury to earmarked guest player Jodie Taylor.

- Coaches union critical of FFA's management review

-Jukic: Australia should no longer accept 'honourable defeats'

That signing, however, never eventuated and City instead turned to American striker Hailie Mace as a guest player in the season's final two weeks.

Though Williams is a 19-time American international -- scoring four goals across those games -- she has not made an appearance at a national camp since April 2018 and wasn't named as a USWNT allocated player in 2019.

A graduate of Pepperdine University, she began her professional career with Western New York Flash in 2015, winning Golden Boot and MVP honours in the Flash's championship-winning 2016 season.

She remained with the franchise when they were sold to new ownership and became the North Carolina Courage; playing a key role in the securing of the 2018 NWSL Championship.

Lynn Williams is set to join the Western Sydney Wanderers for the upcoming W-League season. Quinn Harris/Getty Images

The 26-year-old, alongside Chicago Red Stars' Yuki Nagasato, currently leads the NWSL assist charts, and has found the back of the net seven times across her 15 appearances. She trails only Matildas star Sam Kerr in shots attempted.

When she arrives in Sydney, Williams will provide a much-needed boost in firepower to a Wanderers side that found the back of the net just 11 times as they finished bottom of the W-League in 2018-19; recording just a single win and single draw and 10 defeats.

That poor run of form led to the departure of Dean Barrett as the Wanderers as head coach and the appointment of former A-League player Dean Heffernan for 2019-20. Inaugural Wanderers A-League captain Michael Beauchamp and existing W-League assistant Catherine Cannuli are set to serve as his staff.