The midfield back was a four season veteran of Super 15 with the Chiefs and part of their title-winning squad last year.
But those honours did not stack up for Willison even when Sonny Bill Williams decided to take his skills offshore to rugby league.
Willison felt the selection squeeze as the Chiefs gathered Bundee Aki and Charlie Ngatai to fit in with Andrew Horrell at second five eighths.
However Nonu's change of heart gave Willison an opening as Blues backup to the exciting Francis Saili and after three appearances off the bench, Willison has been picked to start on Friday.
The uncapped Perry made his debut against the Bulls and his strong scrummaging impressed the Blues selectors.
He takes over from Tom McCartney who moved from hooker to cover the loosehead role left vacant when Tony Woodcock also headed south and late to the Highlanders.
Blues: Charles Piutau, Frank Halai, Rene Ranger, Jackson Willison, George Moala, Chris Noakes, Piri Weepu, Peter Saili, Luke Braid, Steven Luatua, Culum Retallick, Ali Williams (c), Angus Ta'avao, James Parsons, Tim Perry. Reserves: Keven Mealamu, Ofa Tu'ungafasi, Anthony Boric, Brendon O'Connor, Jamison Gibson-Park, Baden Kerr, Francis Saili.