A potential big loss is the absence of lock Whitelock who has played in 10 of the Crusaders' 11 matches this year and has been as inspirational as last season when he led the franchise to their title victory in Robertson's first year in charge.
"He wasn't feeling great earlier in the week so we just made a call; we said look 'let's let you freshen up'. He's played a lot of minutes and played some great footy," Robertson said.
"He's extremely driven," he added when asked about Whitelock's potential to take over the All Blacks' captaincy from the injured Kieran Read. "He's got all the leadership qualities to lead any side. The first thing you do [as a captain] is perform well and he's done that for us. He's calm and clear and knows his rugby and his people."
Whitelock's issue, and Robertson wouldn't elaborate, means his side might not be able to capitalise as much on the absence from the Blues' second row of Patrick Tuipulotu, who has been ruled out with a shoulder injury.
The Blues' starting locks are debutant Matiaha Martin, a Counties representative, and Gerard Cowley-Tuioti, with Ben Nee Nee remaining on the reserves bench.
Scott Barrett and the inexperienced Quentin Strange are in the second row for the Crusaders, the current Super Rugby leaders.
Blues coach Tana Umaga has named a relatively settled backline, with Rieko Ioane moving back to the left wing and Melani Nanai in the No14 jersey.
Robertson is aware of the firepower in that backline, while his counterpart made note of the Crusaders' never-say-die attitude.
"Their resilience and ability to bounce back from being down on the scoreboard and having total faith and trust [in themselves]… we have to be consistent with the pressure we put on," Umaga said.
"It's never over with the Crusaders. We saw that last year when we were 20 points up because they will find a way to come back."
Blues:
Matt Duffie, Melani Nanai, Orbyn Leger, Sonny Bill Williams, Rieko Ioane, Stephen Perofeta, Augustine Pulu (c), Akira Ioane, Dalton Papalii or Murphy Taramai, Jerome Kaino, Matiaha Martin, Gerard Cowley-Tuioti, Ofa Tu'ungafasi, James Parsons, Pauliasi Manu.
Reserves: Matt Moulds, Ross Wright, Sione Mafileo, Ben Nee-Nee, Murphy Taramai or Antonio Kiri Kiri, Jonathan Ruru, Dan Kirkpatrick, Michael Collins.
Crusaders:
David Havili, Seta Tamanivalu, Jack Goodhue, Ryan Crotty, George Bridge, Richie Mo'unga, Bryn Hall, Jordan Taufua, Matt Todd (c), Heiden Bedwell-Curtis, Quinten Strange, Scott Barrett, Owen Franks, Codie Taylor, Tim Perry.
Reserves: Andrew Makalio, Wyatt Crockett, Michael Alaalatoa, Mitchell Dunshea, Pete Samu, Mitchell Drummond, Mitchell Hunt, Manasa Mataele.