Central Coast Mariners sit just a point behind them though and a win could change all of that, and they do head into the game with a four-match unbeaten streak.
Match preview
With just a single point between the two teams heading into this Friday, there is plenty to play for as each will be aiming to finish second place to head into the finals series.
Adelaide United do boast the advantage, but a draw would not be good enough considering the fact that Western Sydney Wanderers also sit just a point behind them.
Ruben Zadkovich will be hoping for an improvement in their general form heading into the important finals series as his team are without a win in their previous three matches.
Their most recent outing was a frantic eight-goal thriller that saw them share the points with Perth Glory in a game that featured a frantic finish.
93rd and 96th-minute goals had seemingly snatched a late win for their opponents, yet they went on to score in the 99th to earn a desperate point at the death.
On the other hand, the visitors are undefeated in their previous four matches which is a run that has helped them secure a top-six finish and pushed them into contention to finish runners-up.
While they have technically been stronger at home throughout this campaign, Central Coast Mariners do head into this one fresh from claiming three points on the road last weekend.
A brace from Samuel Silvera and a goal by Marco Tulio were enough to secure the 3-1 victory against Newcastle Jets, who finished the game with just nine men.
Central Coast Mariners have been much stronger at the back this season than their opponents though and that is something they will be hoping to continue ahead of the upcoming finals series.
Earlier this season the visitors dominated Adelaide United with a 4-0 win, and repeating that could provide the ideal momentum for the last stretch of the season.
Adelaide United Australian A-League form:
W
W
W
D
L
D
Central Coast Mariners Australian A-League form:
W
L
W
W
D
W
Team News
Adelaide United are dealing with numerous injury problems heading into the climax of the campaign as Josh Cavallo, Jay Barnett and Harry Van der Saag are all long-term problems.
Nestory Irankunda came off the bench to score a late equaliser last time out, and that impact is something he will be hoping has earned him a place from the first whistle.
Silvera will be sure to retain his place in the starting lineup this weekend after scoring a brace last time out while providing plenty of width at the same time.
Jason Cummings remains an attacking threat for the visitors as well, and after a strong campaign, he should be leading the line.
Adelaide United possible starting lineup:
Gauci; Lopez, Barr, Warland, Kitto; Barnett, D'Arrigo; Halloran, Clough, Goodwin; Ibusuki
Central Coast Mariners possible starting lineup:
Vukovic; Roux, Triantis, Kaltak, McGarry; Nkololo, Balard, Nisbet, Silvera; Cummings, Tulio
We say: Adelaide United 1-2 Central Coast Mariners
Second place is up for grabs in this one and while it might be in Adelaide United's hands, the momentum is behind Central Coast Mariners which should lead to them just edging this one.