Hager wanted his women to scrutinise their start against Ireland during their videotape brainstorming session today.
"I thought our start was very poor. We knew they were going to come and put us under pressure but we didn't play to that," he said, feeling his women opted for "slow hockey".
"We weren't selfish but we just played within ourselves and didn't move the ball quickly. When we got comfortable and we were up we started to move the ball so you can see what happens when we can do that but we'll have to do that for the whole game."
With the game locked at 1-1 into the third quarter, the Samantha Charlton-captained Black Sticks didn't have it all their way.
It took a last quarter flurry in the space of two minutes to whip the crowd into cheers and on their feet.
Ireland had made a bold statement with a 1-0 lead at halftime despite the hosts dominating possession. Their goal came in the 13th minute from a high-fiving Nicola Evans following a goalmouth melee.
New Zealand lynchpin Anita Punt levelled terms, 1-1, just 90 seconds into the second half after flicking the ball into the roof of the net following a penalty corner.
Teammate Stacey Michelsen made it 2-1 in the 52nd minute from the left flank after drilling the ball shoulder high.
The stung Irish were still coming to terms with that when Michelsen became provider to Charlotte Harrison, playing her 200th international, a minute later to extend the lead to 3-1.
"I'm very, very happy," Harrison said. "It was a very nice set up by Stacey so it's very special because I'm playing alongside a great bunch of girls so it means a lot today."
She echoed the sentiments of Hager, feeling they could have started the game better but, in saying that, quite pleased the Black Sticks showed character and resolve to pull away with a two more goals in the end.
"Korea will be a tough game but in the preparation for Rio it's always good to have a hard quarterfinal."
No doubt, for Harrison, like her teammates, Rio is the dream but she has to put in the hard yards.
"It's going to be hard ride so only 16 will go so I'm going to have to train hard and play well to make sure I push for a spot," said the Northland rep who made her debut in 2005, thanking her teammates "for a great journey so far".
Her younger sister, Samantha, is pursuing a degree in education while coaching hockey in Auckland.
"She's doing really well. She's focusing on teaching now but I don't think her international hockey days are over just yet so she'll make a comeback one day when she's ready," the trained beautician said of her 24-year-old former Black Stick.
In other quarterfinal matches tomorrow, pool A top qualifiers Japan play last-placed India, China face non-Olympians Canada, defending champions Australia will cross sticks with Ireland after their 4-0 win yesterday against Canada left coach Adam Commens seething.
