The Magpies started the season with four consecutive wins, but their form has fallen away to the point the Bathgate Park-based team will likely need to win its four remaining games to make the playoffs.
Coach Luke Herden blames his side's slide on poor concentration.
"I think we've got the players who can perform, it is just we're probably lacking composure at vital times in the game," Herden said.
The 17-11 loss to Kaikorai last weekend was a perfect example of that. Southern had the better of the encounter for the majority of the match.
But the team conceded three penalties in a row and Kaikorai got into a position to score a crucial try into the wind.
Southern was also up to its old tricks of missing touch from penalty kicks, and a fumble in the second half from a tap kick proved costly as well. Winger Jordan McEntee scampered away to score from 60m.
"I guess it is our mental application that has let us down over the past eight weeks."
Southern has had to deal with some defections as well. Both starting props have moved on. Hisa Sasagi has joined the Blues, while Mike Mata'afa has joined North Otago club Maheno.
Utility back Josh Buchan has also headed north to Oamaru.
"That has been hard to deal with at times. It has tested the depth of the team but that is not a real excuse.
"We've had opportunities to win games but we haven't taken those opportunities."
Setbacks aside, Southern is still in contention. The crunch part of the campaign starts with Green Island at Miller Park tomorrow.
The Grizzlies have been the Cinderella club this season. But they have also endured a lean run recently, losing three of their last four games.
Their scrum has not held up at all well. It is an area where Southern will look to target them.
If Southern can beat Green Island and University next week, and that is a big ask, its final two games are very winnable matches against Zingari-Richmond and Alhambra-Union.
"It is all knockout football for us from now on.
"We had a good training [on Tuesday night] and the boys are really looking forward to this game."
The game of the round shapes as the match between Harbour and University at the University of Otago Oval. It is a repeat of last year's final.
Harbour has set the benchmark but University has snuck up to fourth after a slow start.
It has not lost since the shock defeat against Dunedin in round seven.
Taieri is the other form side in the competition. It should be too strong for Zingari-Richmond at Montecillo, while Kaikorai will be favourite at home against Alhambra-Union.