Mauger's side went down 31-28 to the Hurricanes in a match which went right down to the wire.
"We played some really good footy. I'm really proud of the effort we put into the performance and we defended really well for large patches," Mauger said.
"But it's gutting. It is tough going. The positive thing for us is we are playing good footy. We played some good footy tonight and executed our game plan well enough to get us to win the game.
"We scored some good points but it was frustrating - just some key defensive lapses and against a team like the Hurricanes they can make you pay."
He said conceding a try just before halftime was damaging to the side.
Mauger was fully supportive of going for a try at the end rather than kicking for a penalty and recording a draw.
He said the spirit of the side was still good and told them they did a lot of good things.
"You can't take anything away from the intent we played with. It was positive. The effort was outstanding and was where we had wanted it all week."
He said there were some good patches in the game and the side just had to get the defensive lapses out of its game.
"We've got to be pleased and 95% of our game is good. And it good enough to get more wins and we have just got to focus on those things."
He said the belief and heart were still there.
"I love coaching this team and being our best every day and make sure we commit every day to that.
"As far as heart, there is plenty of that in our team."
Centre Richard Buckman left the field in the first half and was in a moon boot after the game. He has injured his Achilles and will have it scanned in the next few days.
It has the potential to be a serious injury.
Co-captain Luke Whitelock's calf tightened up near the end and he left the field.
The side takes on the Crusaders in Christchurch next Friday night.