Update: 10:11AM Dan Carter will be at second five-eighth in his first Crusaders start of the Super Rugby season and marking Blues powerhouse Ma'a Nonu in Christchurch on Saturday night.
Back from his sabbatical, Carter played the last half hour in the Crusaders' 16-9 loss to the Hurricanes in Wellington last weekend.
He last wore the No.12 jersey in a handful of games midway through the 2012 competition.
His presence in midfield should add starch to the defence and give the third-placed Crusaders a left-foot kicking option, with the right-footed Colin Slade retaining his first-five position.
With the eighth-placed Blues needing to win their last two games to stay in play-off contention, Carter is expecting a lot of traffic coming his way, led by a rampaging Nonu.
"Trying to stop the likes of Nonu coming down that attacking channel will be a good challenge," he said.
"He's in fine form and playing extremely well and with a lot of confidence. Part of my job and that of the guys around me is to shut him down."
The return to the starting line-up of Carter and captain and No.8 Kieran Read - between them they boast 260 Crusaders appearances - brings much needed leadership and stability to a team that lost the plot against the Hurricanes.
"This is the part of the season we love most," Carter said.
"We're just around the corner from playing finals footy and that's where we want to be."
Read said he was fully over his concussion and confident of playing the full 80 minutes if required.
In all the Crusaders have made six changes to their starting 15.
They include the return of imposing Fijian winger Nemani Nadolo from World Cup duty, and All Blacks Israel Dagg and Owen Franks to fullback and loosehead prop.
The Blues comprehensively beat the Crusaders 35-24 in their round-three match in Auckland, but they have not won in Christchurch for 10 years.