The Steel should be too fit and too polished for the NZNPA team but there are no certainties in sport.
''Some of the girls are nervous about it,'' Southby said.
''But it is a good nervous.''
The Legends team is led by former Silver Ferns and Steel captain Adine Wilson.
She will be joined by a who's who of New Zealand netball. Former Silver Ferns Jenny-May Coffin, Tania Dalton, Anna Galvan, Belinda Colling, Angela Mitchell and Belinda Charteris are all suiting up, along with Stephanie Bond, Jenny Ferguson and Erika Burgess.
All of the Legend players have links to the region, having previously represented the Steel, the Southern Sting or the Otago Rebels.
There are just eight days remaining before the Steel opens its ANZ Championship campaign against the Queensland Firebirds in Brisbane, so it is a final opportunity to tune combinations and work out any wrinkles.
''The biggest thing for us is to get more game time and against a quality opposition. We had a hit-out against the Tactix last week and a few things came out of that, so we are aiming to tidy up a couple of areas of play.''
Jamaican shooter Jhaniele Fowler was forced to spend some time in the defensive circle with defenders Rachel Rasmussen and Phoenix Karaka sidelined with minor injuries. The Steel still managed a four-goal win against the Tactix in Timaru despite a few setbacks.
''I don't think you can read too much in to the pre-season but the thing which was really heartening, is in all of our pre-season games we've shown a real passion and hunger.
''There were times in the game last week where the Tactix really threatened to come back but we knuckled down and played percentage netball.''
''We were a bit guilty last year of letting the ball fly but are really trying to take that out of our game to keep possession and keep the score ticking over.''
Southby hopes the pre-season match against the Legends is a concept which will capture the public's imagination.
''The good thing this year is the players' association has got behind it. The players that are coming are all Steel, Rebels or Sting players. They are all quality players and have all been at the top of the game and know what it is all about.
''So while their bodies might not last the distance, their minds will certainly push and challenge us. I know they will be wanting to put out a really competitive performance and that will hopefully bring a bit of entertainment for the fans. It is also a chance to have a look at where we are at as well.''
