A win for Waitakere over second-placed Tefana - the team they thrashed 10-0 in the opening round - would guarantee them top spot with two games to play.
Waitakere coach Neil Emblen has been forced to make changes to his starting line-up for today's return leg.
Steady defender Tim Myers is suspended, goalkeeper Danny Robinson has stayed home as he waits the birth of a first child and Aaron Scott and Luke Adams, both starters in that romp, are out with long-term injuries.
When Emblen and his players flew out on Thursday afternoon he was still contemplating his options. Ross Haviland and Ross McKenzie, regulars at fullback since that early win, seem certain to replace Scott and Myers but Emblen was tossing up between himself and Matt Cunneen as Jason Rowley's partner at centre-back. Young Matt Upton will step into goal.
"It is always tough over there," said Emblen before departing. "You need the older heads for sure. Our first mindset has to be not to lose the game. I would be happy to come away 1-0 winners no matter how we had to grind it out."
With the need for experience, Emblen has, reluctantly, left some of his younger squad members behind.
Away from the O-League action, most interest will centre on this afternoon's ASB Premiership catch-up game at Porritt Stadium where Hawkes Bay United travel to play Waikato FC in a fixture washed before and then after Christmas.
To keep their only slim play-off hopes alive, Hawkes Bay will need to claim the points and then keep winning - no easy task with trips to Auckland City and Team Wellington and the return with Waikato to come.
Hawkes Bay have had an up and down season - not helped by a change of coach - with good wins over Canterbury United and Waitakere United, but they have been countered by big losses to Team Wellington and Canterbury United.
Waikato have stuck to their task and produced some good results with their basically young squad. In their four home games they have lost to Auckland City, Waitakere, Canterbury United and Team Wellington (by the odd goal in five) - the top four teams in the premiership race.
With games at Porritt Stadium to come against Hawkes Bay, YoungHeart Manawatu and Otago, coach Declan Edge will be looking to add to the seven points they have gathered in a mid-season burst including a 0-0 draw with Auckland City.
Tomorrow in Christchurch Canterbury United will host Otago United in the derby match in the White Ribbon Trophy - instigated to give the premiership sides not involved in the O-League a subsidiary competition.
The winner of tomorrow's game will join Team Wellington at the top of the southern conference with the winner going on to play the northern winner in the April 1 final.
O-League
Auckland City v Koloale
Kiwitea St, today 3pm
Referee: Averii Jacques (Tahiti)
Mont-Dore v Ba
Stade Numa-Daly, Noumea, today 5pm (NZ time)
Referee: Peter O'Leary (NZ)
Hekari United v Amicale
PMRL Stadium, Port Moresby, today 6pm (NZ time)
Referee: Chris Kerr (NZ)
Tefana v Waitakere United
Stade Louis Ganivet, Faa'a, Tahiti, today 6.30pm (NZ time)
Referee: Isidore Assiene (New Caledonia).
