"We've still got a fight on our hands to make the final but that 2-1 loss against China when we played so poorly may cost us."
Hager pointed out his side has played Argentina every year for the last six years.
"Every time it's a tight game but they are the No2 side in the world for a reason."
His troops deserve praise for the manner in which their second half was an improvement on the first. There were far too many unforced errors in the first 35 minutes, too many wrong options and not enough chatter.
However, the Black Sticks' scrambling defence worked well and Argentina's only goal in the half came in the fourth minute from Carla Rebecchi. The pace and skill during the buildup to the goal was superb.
Far too often in the first half the Black Sticks attacked narrow when they would have been better to use the width.
Argentina finished the first half with six shots on goal, two more than the Kiwis and often their players would breeze through the defence.
Argentina's goalie Belen Succi was classy throughout the spell and her 17th minute save of a cracker attempt from Sophie Cocks was superb. Argentina captain and eight-time world player-of-the-year Luciana Aymar gave her side a 2-0 lead four minutes into the second half with a field goal.
Black Sticks midfielder Anita Punt scored her team's first goal from a penalty corner in the eighth minute. With 16 minutes remaining Punt executed a similar shot from a penalty corner, which was deflected in by captain Kayla Whitelock.
Four minutes later Succi saved a cracking penalty corner shot from Punt. With the Friendship Cup looking like it was going to be shared and four minutes remaining Rebecchi scored her second goal much to the delight of a small contingent of Argentinian supporters who had been relatively quiet for most of the second half.
Yet again Hager had to congratulate Argentinian coach Carlos Retegui, a bloke he had played against during his days as an Australian representative.
Black Stick Gemma Flynn had some memorable moments on the counter attack while Punt and Whitelock often displayed the benefits of their experience.
One of Hager's relative newcomers to impress was Canterbury midfielder Jordan Grant, who shone with her defensive work.
"Yes and no," replied the St Margaret's College product when asked if she was happy with her individual contribution.
"Some things I did well others I didn't."
Hager said apart from an occasion when the Argentinians stole the ball off her and scored he was happy with her input.
He pointed out the 23-year-old is normally a striker so is learning a different position.
Grant first played for the team last month.
"That's definitely the toughest team I've played against. At halftime Mark talked to us about a few things ... getting in front of them and chasing the ball all the time. We did that well for long periods," Grant added.
Earlier yesterday, Australia walloped China 4-0 and Korea beat Japan 3-2.
At one point in the Korea-Japan game play was delayed because of heavy rain.
At halftime the score was locked at one-all, but the tempo was raised when Korea struck early in the second half with a goal to Kim Darae.
Japan quickly responded with a set move off a penalty corner, however, it wasn't enough to stave off a late Korean assault, with Cheon Seul finding the net in the dying minutes.
Against China the world's fourth ranked side, Australia, asserted their dominance early, with goals to Georgia Nanscawen and substitute Mathilda Carmichael. In the second half Australia consolidated their lead with a strong attack in the final quarter seeing Kellie White score twice.
