Williams has yet to announce her new club, although defending champions Melbourne City are considered favourites to sign the shot-stopper.

Williams helped United to two W-League premierships since joining the team as a foundation player in 2008.

Dower said United would unveil Williams' replacement later this week and was confident the team could move on.

"One door closes in one respect and another door opens," Dower said.

"As soon as we were aware that Lydia wasn't coming back our focus was firmly on somebody to replace her and moving forward with the team."

Meanwhile, Dower said the formation of the national women's Australian football league would complement the W-League rather than poach talent.

A number of United players have been linked with AFL women's teams, including Jenna McCormick and Ellie Brush, as well as the injured Caitlin Munoz, who attended a talent search session with the GWS Giants.

But Dower said the two codes would not compete with each other and the advancement in women's sport was a "win-win".

"The seasons only overlap by a couple of games and obviously they're both endurance-based sports with collisions as well, so if there is the opportunity for the players to do it, and both the organisations want to do it, then it's a win-win," she said.

"The more that we can have female athletes become professional athletes and play professional sport throughout longer periods of the year then the higher the profiles of the female athletes will be.

"There is certainly room for us to work together, rather than in competition."

A number of basketballers have presented as code-hoppers, with Opals star Erin Phillips signing with the Adelaide Crows, as well as Jessica Bibby training with the Giants.