The veteran coach has a core group of experienced players he knows he can rely on to score runs and take wickets. But he has to squeeze more out of the next group of players and that means providing them with more opportunities.
''We don't want to rely on the top three or four players, so it is really important for the next group down. They've got to step up.''
White Ferns captain Suzie Bates and experienced wicketkeeper batsman Katey Martin have carried the Sparks batting order for the past decade, while more recently spinners Leigh Kasperek and Morna Nielsen have also had a big impact.
When those four have gone well, the Sparks have gone well. And in a format such as twenty20, there have not always been opportunities for the other players in the squad to shine.
Lees intends to provide more chances for the likes of Caitlin Blakely, Ella Brown, Georgia Clarke, Millie Cowan and Polly Inglis.
''In twenty20 you can end up batting at No8 and not bowling much and don't get opportunities to perform or even improve. That is the way it is. You can't change the world.
''But I want to change the batting order around. I want to say to one of these girls 'You have to bat No3 today'.
''While we want to win, and that is what we go out there for, I might be able to sandwich one of these players between a Katey Martin or a Suzie Bates.''
But Lees does not want to completely sacrifice results at the altar of development. The one-day tournament carries more meaning for Lees, who describes himself as a ''traditionalist'', so supporters can expect to see the bulk of the experimenting done in the shorter format.
The squad has a very settled look, with the only newbie wicketkeeper-batsman Shebani Bhaskar.
She lives in India but is a citizen of the United States and has represented the associate nation.
The 21-year-old is principally a batsman, but she can bowl as well as keep. She arrived in Dunedin earlier this week and hopes to force her way into the starting side for the Sparks.
Batsman Bella James will miss a good portion of the campaign while in the United States with her family.
The Sparks will get around the region during the preseason. They were in Gore recently and will visit Naseby and Millbrook this weekend, and have trips to Alexandra, Luggate and Oamaru planned.
