A fiery Sydney Derby, fresh off the memory of a famous 5-0 drubbing, seems like too-fitting a time for the W-League to issue its first red card of the season.

But Kristen Hamilton's deserved send off, given her marching orders after an unnecessary sliding challenge towards the match's conclusion, is a very worrying sign for her club.

Western Sydney began the season with, what many lauded, as the best strikeforce the league had ever seen: reigning NWSL champions Hamilton and US national team regular Lynn Williams.

After the Wanderers barnstormed their way through the opening few rounds undefeated, things got even better.

Promising Young Matilda Kyra Cooney Cross exploded under her experienced internationals' guidance, soon forming a prodigious attacking lineup that struck fear into even the most ardent Dub defences.

But flash forward a few months and the Wanderers decline is beginning to appear just as shockingly swift as their rise.

Now riding three losses from their last four and an injury list to match their transfer window departures, fans have gone from pondering whether Western Sydney are Championship contenders to questioning whether they'll even make finals.

The Wanderers now sit third but could be fourth after Melbourne Victory play tomorrow. If Brisbane Roar win, the gap between the Wanderers and no-finals will be a narrow two points. Unthinkable at the beginning of the season and made worse by the fact that Brisbane smashed Western Sydney 4-0 a matter of weeks ago.

There is room for optimism - the Wanderers' maestro, Lynn Williams, is set to return from a lengthy international absence shortly. She can't come soon enough for Dean Heffernan's side, who have all but collapsed without her.

But in the meantime, the once-incredible array of international talent Western Sydney boasted at the beginning of the campaign will be cut down to just one, US defender Sam Staab.

Meanwhile, perhaps more worrying is how the absence of internationals has coincided with a loss of form and discipline. Hamilton's needless red was one factor, but their 3-0 Derby loss was punctuated by strange decisions across the pitch.

Towards the end of the match, reserve keeper Courtney Newbon dallied on the ball, eventually losing it in front of her own goal-line, only for Staab to attempt to take on two attackers in front of an open goal.

She was lucky to see what should have been a simple situation out for a Sydney corner.

For a club that less than 12 months ago was a perennial cellar-dweller, the club's sudden impetus to make finals may seem like a first world problem.

But the Wanderers have invested record-breaking amounts to make it this far and it would be a devastating blow to lose it all now.