"It got to the stage where even two laps of trackwork would be unbearable," says Colgan.
"I really thought about giving riding away and it was incredibly frustrating because we couldn't diagnose what was wrong, or how to fix it."
Retirement loomed, a deflating end for one of the characters of New Zealand racing.
But Colgan chose surgery and the discomfort of recovery, refusing to give up at an age when few could have blamed him.
He has been back riding for 16 months, and while the talent hasn't faded, opportunities at the highest level are harder to come by, not helped by suspensions such as the one that cost him the Captain Cook Stakes on Two Illicit in December.
Ironically, it is the suspension of Craig Grylls that has put Colgan back in La Crique's saddle after Colgan was her first rider and he says he is ready to turn back time to his days as the Derby dominator.
"I still enjoy the riding, now the pain is gone," says the now 46-year-old. "But I don't get these sort of opportunities much any more. Horses like La Crique don't come along very often, so I'm going to enjoy it. The very first time I rode her, I knew she was special."
Drawing barrier one saw La Crique shorten into $1.85 favouritism but Colgan says he would have preferred a barrier from four to six and a guaranteed spot in the running line with less chance of getting locked away.
"She has the tactical speed to use the ace and I think she will probably end up in trail but I don't want to follow a horse that might stop on her. But I'll have some say in that, and if we get a good, even tempo, she'll be too good for most of them because it's hard to make a case for the horses who finished behind her in the Guineas beating her home."
The only horse to really stand out as a danger to La Crique is Pinarello, the horse Colgan won on two weeks ago, then jumped off to ride the favourite.
"He's a good horse, very different from the filly, but a real Derby horse. He will follow the speed and then sprint hard late, so he can win for sure."
Pinarello is also co-trained by Roger James, who has won the Derby five times, three with Colgan in the saddle.
Colgan has ridden all sorts to win the Derby, from those three for James (Roysyn, Zonda, Hades), an Aussie in Redoutes Dancer, a filly Habibi (2013) and Rangipo (2016) for another key rival trainer today in Tony Pike.
Pike has one of the upset hopes today in Tutukaka, while trainers who know how to win derbies in Murray Baker and Andrew Forsman have three hopes today, so the classic will be no Ellerslie stroll for La Crique.
With that slight possibility of traffic concerns, those investing heavily on La Crique should look at cover on Pinarello, who appears clearly the best of the swoopers and gives the likely winner on two different scenarios.
But if the filly gets clear air and a fair shot somewhere between the 600m and 400m, Colgan should get his magnificent seven.
