Collins (26) will lead Otago into battle tomorrow afternoon in the side's Ranfurly Shield challenge against Waikato at Forsyth Barr Stadium.
The fullback is coming off a nasty groin injury, known as Osteitis pubis, which scuttled much of his Super Rugby season with the Blues.
The condition involves tightening and damage around the pubic area and is a condition which strikes many sportsman.
It leads to an inability to run and stretch out, pain in the pelvic area, and has led to the forced retirement of players, especially in Australian football.
Collins never got that bad but it was a frustrating time for him.
"You sort of have to teach yourself how to walk again, run again, how to move again and in a way that doesn't load that bone," he said.
"I had to start from scratch again, and learn how to move and when I got to a stage of running around ... it was a good five to six months all up of teaching yourself how to move again."
He consulted a specialist in Australia and other medical experts but it gradually came right.
"It has been a really interesting challenge. It is something that will be ongoing for my career now ... about pre-hab and re-hab now you have got these sort of injuries. I have learnt more about my body in the last five to six months than I ever had."
Collins had an abductor tear earlier this year at the Blues but, with competition for places, he kept playing.
"I ran on an abductor tear for a while and because of that I moved in a different way. I would never say my running style has been good to start with.
"But that made it worse and because I was running in a different way, I was loading different parts of my body that I shouldn't have. Over a few months it started wearing away and got into my nerve endings and started tearing things apart."
He never considered hanging up the boots and is now looking forward.
"You just work through it, learn things about my body and look forward."
Collins is now back to full fitness and looking forward to taking on Waikato tomorrow.
"I love being back down here. Otago is a pretty special place. And this is a special time to be part of Otago rugby."
He has signed with the Highlanders next year and is looking forward to being part of a new generation with the side.
"Obviously, they have had a massive loss of players last year so it is an exciting part of time being with the Highlanders.
"It is exciting to being a part of what Aaron [coach Aaron Mauger] is building and having Browny [assistant coach Tony Brown] back."
First though is Waikato tomorrow.
"The team is excited, I think. It is nice to be at home under the roof. Playing Sunday afternoon footy is perfect.
"Playing for the shield brings a bit of extra heat. We just do our best to worry about us and worry about the game. But I think there is going to be that edge around the game."