Western Sydney Wanderers face Adelaide United on Sunday, with both hoping to banish memories of A-League grand final heartache.

Despite playing in four of the A-League's 10 grand finals between them, neither has a championship to show for their efforts.

On Sunday, it will be third time lucky for one of them.

In front of a packed out home crowd at the historic Adelaide Oval, United will be looking to change all that in their favour.

Adelaide - losing finalists to Melbourne Victory in 2007 and 2009 and minor premiers this season after sitting bottom in the table after round eight - enter the game as favourites, not just because of their home advantage but because of their magnificent form which has seen them lose just one league game since November.

United coach Guillermo Amor has masterminded the club's fairytale rise from cellar dwellers to premiers and while his team might not be recognised for instances of individual brilliance - as noted by the lack of any Adelaide players in the Australian PFA team of the year - his side's ability to blend strong defensive structures with slick offensive movements makes them a match for any team.

That was noted in the semi-final, where they comfortably saw off Melbourne City 4-1, in the manner that they completely nullified arguably the league's two best players in Aaron Mooy and Bruno Fornaroli.

One player that does stand out, however, is Isaias and the Spaniard says Adelaide have already been playing every game like a final after their horror start to the season.

"Our mentality before was to play game-by-game, every game is a final," the Spaniard told reporters in Adelaide. "And of course this weekend is the biggest final. Absolutely we are excited to play this kind of game."

But as good as Adelaide have been, the Wanderers have made a habit of defying the odds.

Less than two years after coming into existence, Wanderers were continental champions, after winning the 2014 Asian Champions League, but lost the 2013 and 2014 A-League showpieces to the Central Coast Mariners and Brisbane Roar respectively.

Head coach Tony Popovic has made a habit of winning, and he will be hoping to add one of the few trophies that have eluded him as Wanderers boss to the cabinet on Sunday.

Captain Nikolai Topor-Stanley played in both those losses, but he is ready to right the wrongs of past seasons.

"I'll carry that disappointment forever. You never get over that," he told reporters. "You never know when your next grand final is going to be but lucky enough we have another opportunity on Sunday.

"Time's ticking for me especially. In four years of being here, you never know if I'll get another opportunity at this club or even elsewhere. Whenever you get a chance to play and be crowned champion you really need to take that on."