The Black Sticks take on Korea, Netherlands and then Germany while on the other side of the draw Argentina, Great Britain, Australia and China face each other before a must-win quarter-final clash.
Gemma Flynn and Emily Naylor will make their return after missing the recent Oceania championships but former captain Kayla Whitelock is still absent, having given birth to a baby girl six months ago. Striker Katie Glynn was still out with a long-term back problem but had been training four times a week and goalkeeper Amelia Gibson was also ruled out due to injury.
Hager said Whitelock and Glynn would both be training over the Christmas period, with a goal of returning to play in 2016.
"We're very keen to start to step up and win games that are close games," he said. "We're not hiding behind the fact that at the moment we're not doing that and we're working very hard technically and also on our mindset to try and change that."
Having Flynn back on the squad was "hugely important", midfielder Anita Punt said, as well as having Whitelock and Glenn in the background.
"It just helps out so much - their depth, their experience - it's just going to help the younger girls to come through," she said. "It's always handy having someone with Gemma's experience and she's in fine form at the moment with her hockey."
Flynn is the New Zealand women's side's fourth-highest goalscorer of all time with 62 but missed the Oceania championships when she had a break from hockey.
She knows the Black Sticks need to improve their record in close games.
"Those semifinals are the crunch games and we need to score goals and defend well," she said. "I'm excited and it'll be fun going over to Argentina and challenging ourselves against the worlds' best."
Despite the Rio Olympics looming large on the horizon, Punt said the team was not treating the upcoming tournament merely as practice for the big event. The Black Sticks will have played 34 internationals by the end of the year.
"We have to use this as a learning curve for Rio, but we're not going to go out there just to practice," Punt said. "We want to go out and win."
Intra-squad competition had helped the team prepare immensely, Hager said, with younger players from the junior programmes joining in on the games. Hager will announce a 25-strong Olympic squad at the end of the year.
"Some of those kids show some really good signs and that puts pressure on our current players," he said. "That's what we want - we want to be healthy, we want to be moving forward and I think that's one of the things that can help us win those close games, the competition against each other."
Black sticks women's squad: Emily Naylor, Olivia Merry, Petrea Webster, Sally Rutherford, Brooke Neal, Ella Gunson, Sam Charlton, Liz Thompson, Sophie Cocks, Kirsten Pearce, Georgia Barnett, Gemma Flynn, Charlotte Harrison, Rose Keddell, Pippa Hayward, Kat Henry, Stacey Michelsen, Anita Punt.
