Former Blues player Tim Perry retains his place at loosehead prop ahead of Wyatt Crockett.
Blackadder dropped Dagg, a consistently good performer for the All Blacks, last year after a run of mediocre matches but has acted much earlier this season.
Crusaders team to play the Blues at Eden Park on Friday, kick-off 7.35pm is: Colin Slade, Rob Thompson, Reynold Lee-Lo, Ryan Crotty, Nafi Tuitavake, Tom Taylor, Andy Ellis, Kieran Read (c), Richie McCaw, George Whitelock, Dominic Bird, Sam Whitelock, Owen Franks, Corey Flynn, Tim Perry. Reserves: Ben Funnell, Wyatt Crockett, Nepo Laulala, Luke Romano, Matt Todd, Willi Heinz, Adam Whitelock, Israel Dagg.