It looked like he'd done the very thing he'd been warned against doing - and he'd stopped trusting his instincts. "For sure," he says. "I found last year I was too worried about running straight and trying to be the perfect player and I was worried about what other people might think.
"When you are a young guy you don't do any analysis on what teams you are playing or the guy you might be playing. You don't study any player - you get out there, you see a hole, you take it - you play what you see.
"My coach when I was growing up, Grant Gilbert, he always says 99 per cent of the time, your instincts are going to be right. And if they are not, just give everything 100 per cent and it will probably turn into the right thing."
Dagg's reticence to back himself, his obvious indecisiveness when he played and lack of spontaneity led to him being called by Hansen on the day the 2015 World Cup squad was named. It was the bad news he had expected but dreaded.
"I was going to make some rash decisions and leave," Dagg reveals. "But I took the time to breathe."
And once he calmed down, processed the hurt, he started to try to tap into the essence of himself. He tried to figure out what had gone wrong and how he could make things right again.
The more he thought about it, the more it became clear - he'd stopped enjoying it. At his best, Dagg played with a smile on his face. He was a free spirit - never loose or reckless, but always willing to explore.
When he got it right - which was most of the time - he'd let everyone know he'd enjoyed it. When he got things wrong, he'd shrug and smile just the same, to acknowledge that the fun came as much from trying as it did succeeding. He decided, when the All Blacks were at the World Cup, that he wanted to stay in New Zealand and rediscover his love of the game.
"It wasn't about trying to prove anyone wrong or prove anything to anyone else," he says. "I just had to go out there and find why I play this game ... and I play this game because I love it. I have fun and I have fun expressing myself, representing my family, my country and the Crusaders."
With his head clear and his body having benefited from an extended off season that was forced by shoulder surgery, it took him just one game to reconnect with rugby.
His return for the Crusaders, against the Jaguares in early April, was an immediate success. He was the Dagg of old - hungry to be involved, willing to run where his legs took him and not once did he get caught in two minds wondering what to do.
He caught the ball and ran - it was that simple and his sharpness, agility and acceleration were all once again visible. He'd rediscovered his joi de vivre and earned himself, in the space of barely a month, a guaranteed recall to the All Blacks.
And tonight his journey will take one more step back to the familiar, when he slips into his once treasured No 15 jersey and wins his 50th test cap. It's a landmark that he says he had real doubts about ever reaching.
Hansen, on the other hand, never lacked confidence that Dagg would return. His faith was always strong. "The reason he didn't get picked for the World Cup was that he got injured, he just lost form and by his own admission he wasn't enjoying the game," says Hansen. "If he was going to recapture that love for the game and ... have a decent crack at a pre-season the odds of him coming back and playing well were pretty high.
"We know that if he plays well, he is one of the best in the world at what he does. It was just a matter of time and he has played really well for the Crusaders and I would expect him to hum on Saturday night."
Dagg hopes much the same and the big difference between him and this stage last year when he was a shadow of his true self, is that he's not tying himself up in mental knots thinking endlessly about what he has to do tonight.
It's all so simple for him now. "I have just got to go out there and play how I play and do my job."
