This team, with an average age of just over 23, has belief and spirit. Most importantly, Hager has revolutionised the style and approach of the Black Sticks women, and the hockey world has noticed.
"They play a lot like Mark used to play," Argentine coach Carlos Retegui told the Herald on Sunday. "They have flair, skill and pace. New Zealand has become a very dangerous opponent."
"Four years ago, I didn't know [what] style New Zealand played," says Natascha Keller, Germany's flag bearer at these games and the most capped female player in history. "The last two or three years they play like the Australian girls. They are very fast, they run and and they make a lot of goals. We [have] noticed that they are not easy to play against now."
"They have grown a lot and made a big step," says Dutch star Naomi van As, who took gold in Beijing.
"They have become more attacking and their skills are much better than before."
That is the crux of the Hager makeover. He has built a speedy, super-fit team and put the emphasis on positive attacking hockey. He expects this team will peak in the next couple of years. Hager is loyal to his players but has been careful to create a competitive environment.
In December, Hager identified five players who were certainties for his London squad. A few days later he asked the Herald on Sunday if we could leave that part of the interview out of the story, as he didn't want anyone in his team getting complacent, thinking that they had already made it.
He also doesn't suffer fools, and is not afraid to read the riot act. At the end of the disappointing Champions Trophy campaign in Argentina earlier this year, he raised questions about the mental toughness of his team.
"We are not tough enough at the moment," Hager said. "We get in front, but we can't hold it and it is an issue we have to address going forward.
"Mental toughness comes from within. It comes from digging deep; the will to win, and win every one-on-one contest. At the moment we have players who do that, but I don't think collectively as a team we are doing it well enough. We'll have to dig deep when we get home and they'll be put through the wringer."
The former Australian striker, who scored a record 179 goals for his country, retains the ability to see what might unfold before most of the players. His halftime talks are incisive and passionate. He has also turned his players into students of the sport, with an increased focus on their foes.
"With [previous coaches], it was very planned and structured, but it was mostly about us," says veteran striker Krystal Forgesson. "Mark is very good at keeping up with what other teams are doing and we are always learning about them. He is always on our case about looking on YouTube and websites to follow what other teams are doing."