"The group of players that come in will now get their chance to perform, to show what they can do," says Hager.
Hager estimates the team played at about 45-50 per cent of their potential in Argentina and hopes this series will see that rise to around 65-70 per cent.
The Blacks Sticks have prepared with a physical challenge, playing against various male teams including Westlake Boys High, the Auckland under-21 team and their North Harbour counterparts.
New Zealand fancy their chances against the powerhouse South Americans.
Argentina have been bolstered by the presence of Luciana Aymar, seven time FIH world hockey player of the year, though the Herald on Sunday understands she will miss the first test because of an Olympic committee commitment.
Las Leonas also received a major setback last week, when penalty corner drag flicking specialist Maria Barrionuevo injured a knee. She won't make the New Zealand tour and is in some doubt for the Olympics; Carla Rebecchi is a capable replacement but not in the same class as Barrionuevo.
The first test is tomorrow at 6.30pm at Lloyd Elsmore Hockey Stadium, with subsequent games on Wednesday (Albany), Friday (Lloyd Elsmore) and Saturday (Albany).