United loom as the wild card to win the championship and will take plenty of momentum into Saturday's elimination semi-final against the Melbourne Victory at Simonds Stadium.

Central defender Ellie Brush has made the trip to Geelong after passing a fitness test on her injured ankle at the team's final training session in Canberra on Friday.

Midfielder Grace Gill has also been included in an extended 17-player squad.

United finished third on the table after a roller-coaster season capped off with a 2-1 win against minor premiers Perth Glory knowing they needed at least a point to reach the finals.

Fletcher has been a valuable addition since joining the team in round seven, bolstering a then injury-depleted squad to upset the Victory 1-0 at Etihad Stadium.

The American's early arrival for her seven-game guest stint means she will have to watch from the sidelines if United progress to the decider.

Fletcher has played in the semi-finals in each of her previous four seasons in the W-League with the Central Coast Mariners, the Victory and Canberra, but has yet to reach the grand final.

"Hopefully I can reverse the curse and get the team to the final and that would be a huge win in my book," Fletcher said. "It's actually poetic and I like it.

"Obviously it's disappointing from a personal standpoint that I won't be able to play in the final, but I knew that coming in as a guest player. I'm happy to play my role and get the team there."

United are hoping to make amends for last season when they finished at the top of the table at the end of the regular season, before losing in the semi-finals.

This year has been a different story.

While United have managed wins against the top two sides in the competition, they have also dropped points to all three teams that missed the finals.

United striker Michelle Heyman - who scored against Perth last week - believes the side can use their late surge to their advantage.

"It doesn't matter if you come first any more, so it's always good just to make the final four and we don't have all that pressure on us," Heyman said.

"It's been a weird season. We trained really well, our finishing wasn't the greatest even at training, but lately, the last three weeks, we're putting everything away. Things are finally coming together and hopefully that just keeps rolling on for us."

United will be hoping to give veteran US midfielder Lori Lindsey the perfect send-off.

The 34-year-old is hanging up the boots at the end of the season, ending a career spanning more than a decade at the top level and more than 30 appearances for her country.

"I'm trying not to concentrate on this possibly being my final game," Lindsey said. "I'm proud of my career and this is the decision I've made, so it hasn't come out of the blue. I'm looking on the positive side and thinking this isn't the last game and I do believe we can win."

Canberra will host the grand final if they beat the Victory and Sydney FC upset Perth Glory on Sunday.

W-LEAGUE: Semi-final: Canberra United v Melbourne Victory at Simonds Stadium on Saturday, 3pm. TV: Live on ABC 1.