Eastern Suburbs awaits in the team's final game of the season, today in Auckland, with kick off at 4pm at River Hills Park.
Last time the sides met, Southern was thrashed 6-1 on a wet day at Sunnyvale Park in the first game after the Christmas break.
It was the side's biggest loss since January 2016.
The week after it was edged by Auckland City, but has since gone undefeated in seven consecutive games.
If it is to extend that streak to eight it will have to take points off Eastern Suburbs.
That is something it has never done, Suburbs having won all five previous encounters.
To make things harder, Southern will be without several of its top players.
The most notable absentees are Tony Whitehead and Danny Ledwith.
Both have been key in the midfield this season, but picked up their fifth yellow cards last weekend and will miss the match.
Azariah Soromon will also be away with the Vanuatu team.
A draw and a point would also equal last year's total of 24 points.
That would mark an impressive season, as backing up an improved performance is never easy.
Suburbs has been the league's most dangerous goal-scoring team.
It has netted 50, nine more than Auckland City, and conceded just 16.
Callum McCowatt and Andre de Jong have been the two most prominent players in that regard, scoring 16 and 15 each.
Only Hawke's Bay United's Sam Mason-Smith - who has scored 16 - has been that prolific.
Southern United striker Garbhan Coughlan has scored 13 goals this season.
Eastern Suburbs has little to play for, in a competition sense, as well.
The Auckland team has 37 points, which leaves it 12 behind runaway leader Auckland City and four in front of Canterbury United, which holds third place.
What the playoff match-ups look like will be decided this weekend.
Canterbury has a two-point edge over Team Wellington.
A win in Nelson against Tasman United would secure third spot and avoid a semifinal against Auckland City.
However, a loss or draw would open the door to Team Wellington to get into third.
Southern United will want to be more deadly in front of goal after last week, when it drew 2-2 with Hawkes Bay.
If it had converted even half of its chances, it would have been a comfortable home win for the southerners.
Whatever happens today, it has been a good season from a side which has come a long way in the past couple of years.
It will be an interesting off-season as plans are discussed around the future shape of the league and the inequity between different teams.
Most players for Southern United will disperse while the local players do not have much time to put their feet up as the Football South Premiership kicks off next week.
