"Early on when I was still in a straight leg brace that was tough, but we started making some good progress early in rehab and then there's a couple of moments where it just doesn't seem to be getting any better and it's still really sore, but it was just a process that took a long time.
"I know it's going to be a bit of a shock for the body but I know I'm fit enough at play at this level."
All Black lock Sam Whitelock also returns after four weeks off with a broken finger while Joe Moody has been ruled out of the tour of Australia with a knee injury he sustained against the Blues, meaning fellow All Black George Bower will start at loosehead prop and Tamaiti Williams joins the reserves.
There are two further changes in the Crusaders backline to face the Rebels, with Mitch Drummond joining the run-on team at halfback in place of Bryn Hall, while Will Jordan will sit out this weekend's match and George Bridge takes the starting spot at fullback.
Codie Taylor will captain the side in the absence of the suspended Scott Barrett.
Crusaders v Rebels
Sunday, 6.30pm, Melbourne
Crusaders: George Bridge, Sevu Reece, Braydon Ennor, Jack Goodhue, Leicester Fainga'anuku, Richie Mo'unga, Mitch Drummond, Cullen Grace, Ethan Blackadder, Pablo Matera, Sam Whitelock, Zach Gallagher, Oli Jager, Codie Taylor (c), George Bower.
Reserves: Ricky Jackson, Tamaiti Williams, Fletcher Newell, Dominic Gardiner, Corey Kellow, Bryn Hall, Fergus Burke, Chay Fihaki.