"When we do things the way we want to and have confidence in ourselves and each other then we can play some really good netball."
The Silver Ferns most recent performance raised questions about their lack of mental strength and ability to deal with the pressure of critical moments, particularly with the Commonwealth Games fast approaching.
But Grant said, as they would with any loss, they would strive to make it a learning experience.
"If we take it as learning, it will be a good thing for Commonwealth Games because next time we go through it we will know how to react and how to deal with it," she said.
"If we don't learn from it, it will be a concern because a lot of players in our team have not been through that before."
Grant said they expect a tough battle from the Proteas, after South Africa showcased a strong performance against the Australian Diamonds earlier this week.
The Proteas narrowly lost to Australia 54-50 - the Diamonds smallest ever winning margin over South Africa.
"They will be full of confidence," Grant said, "They really gave Australia a run for their money the other day and they looked really fit, athletic, fast, they are playing some really good netball."
"They've got accurate shooters and defenders who just run through the ball so we've got to be completely on our game to take the match."
The Fern's starting 12 was announced earlier today with Jane Watson and Maia Wilson back on board.
Defender Phoenix Karaka will sit out tomorrow's game alongside one of the Silver Fern's youngest players, Whitney Souness.
The Silver Ferns will face the SPAR Proteas at (NZT) 6am on Friday morning.
Silver Ferns Team for the 2nd Test of the Netball Quad Series:
Katrina Grant (c) Maria Folau (nee Tutaia) (vc) Kayla Cullen Temalisi Fakahokotau Shannon Francois Kelly Jury Grace Kara (nee Rasmussen) Bailey Mes Te Paea Selby-Rickit Samantha Sinclair Jane Watson Maia Wilson
Silver Ferns goal shoot Grace Nweke speaks about the Constellation Cup series and the rivalry against the Diamonds in the final match. Video / Alyse Wright