He is not really living up to the tag ''Hagar the Horrible'', although some of his training sessions are certainly memorable.
He is not shy to push the squad harder in training than they are likely to have to work on game day. The dreaded ''red'' sessions are the worst.
But then the Black Sticks' whole game plan is based around fitness and speed, so there is nothing terrifying about the 54-year-old, really. In fact, he is a bit of a softie.
There is nothing he hates more than explaining to players why they have missed out on the squad.
''Having to tell players they are not in teams does wear you down,'' he said.
''You don't want to break people's dreams but, unfortunately, that is part of the job.
''Talking to the athlete afterwards is the hardest thing and I don't like it. I'm a moody bugger when it comes up.''
Hager's wife, Michelle, who is an Olympic hockey gold medallist for Australia, probably bears the brunt of his moods.
The couple have three daughters - Shannon (23), Teegan (20) and Keely (17). The youngest plays hockey in Dunedin and studies at the University of Otago.
Hager took over the Black Sticks' reins in 2009 and the squad has had its share of heartbreak during that time. The two fourth placings at the Olympics spring to mind.
But beating Australia 4-1 in the gold-medal match at the Commonwealth Games on the Gold Coast last month helped ease some of that sense of disappointment.
''I felt so pleased for the all the girls and all the people who have worked for us over the last 10 years, or even before our time.
''To finally get over the hurdle, I suppose, of playing in a final, a semifinal or a shoot-out and actually winning it was pleasing.
''It gave us a little bit of confidence but we now have to come back down to earth and realise we have a world cup.
''So we need to start again and get better again.''
The world cup is in London is a couple of months and the Blacks Sticks are preparing for it at the Tri-Nations tournament in Cromwell this week.
They lost their opening games against Japan and Australia but the tournament is a bit of a ''cat and mouse'' exercise.
All three teams are in the same pool for the world cup and the Black Sticks are holding back some tricks.
That said, Hager felt the team needed to improved its discipline. There had been too many cards and the defence had not been as polished as usual.
But you can learn a lot from defeat as well. The Olympic campaigns proved that.
''You have to play in those sort of tournaments and finals to learn what it is like.''
Hager would like one more shot at the Olympics. He is contracted through to the end of 2020.
''I think they will need a new voice after that.''
''But it is hard to say. You never know, if we do really well then the enthusiasm might be there to go again.
''But at this stage I'm probably going to give it a break and look to do some other things.''
He plans to continue coaching and wants to stay involved with Hockey New Zealand, so chances are he will not be lost to the organisation. The succession planning has already got under way, though, with assistant coach Sean Dancer standing in for Hager in Cromwell this week.
