The Steel, which squeezed into the playoffs despite winning just three games during the regular season, is preparing to play the Waikato-Bay of Plenty Magic in Hamilton on Saturday.
A win would enable the Steel to advance to the New Zealand conference final in which it would play the Northern Mystics in Auckland on Monday.
With three wins, two draws and eight losses this season, the Steel clinched the third and final playoff spot in the New Zealand conference, but it goes into the playoffs with the third-worst record in the competition.
''I know there's going to be lots of comments about the conference system, but the reality is it was there at the start of the season and it hasn't changed now,'' Southby said.
''We certainly wanted to get there with a little bit more of a bang than to limp in, but we're there and we're going to make the most of our opportunity.''
Saturday's conference semifinal against the Magic will be the Steel's first playoff game since 2010, when it lost to the Magic in the semifinals.
Captain Wendy Frew is the only surviving member from that match, making her the only player on the Steel roster with playoff experience in the competition.
That is one more match than Southby, who has been with the team since 2012.
''I still think it's going to come down to us being able to execute a full 60 minutes of netball.''
Southby has been seeking that complete performance all season, and will probably need if it is going to topple the Magic for just the sixth time in 18 attempts.
The Steel has shown it can compete with the best teams in the competition for portions of games, but has a habit of fading when it matters most.
However, Southby said the team was putting the regular season behind it and starting with a fresh mindset.
''We obviously can't wipe what we have learnt over the season, but I think it's about making sure we have learnt from those games and now it's anyone's game. That's the attitude we need to take into the playoffs,'' she said.
The Magic, which beat the Steel twice during the regular season, will be a different proposition with Silver Ferns captain Casey Kopua back from a lengthy knee injury.
She was unavailable for the two games against the Steel, but returned to the court a few weeks ago and has gradually been upping her workload.
''I have total respect for the Magic,'' Southby said.
''I know having Casey back in the group adds to their confidence, but I think it has to be about us. I know when we are confident we attack, that's attacking in defence and attacking on attack. We are fine and we know that we can compete and beat teams when we do that.
''That's the challenge for us.''
The Steel had a light gym session yesterday, and will train as a team today and tomorrow.
