"Tough sport we play in. He's got a few more years with us so he'll come back and rehab hard."
Robertson said Moody typically downplayed the news, but admitted the 33-year-old prop was disappointed: "He's a man of few words. There were a couple of deep breaths on it, not much was said."
With the Rugby World Cup approaching next year, Moody will be in a race for time to get fit and fight back into the black jersey, but Robertson is backing his prop.
"Joe has got some grit in him. As we know, he can fight out of some pretty tough situations in those scrums. So, this is another tough situation for him to fight out of. We're right behind him."
With Moody turning 34 in September, there are questions over whether this latest injury could mean the end his career.
However, Robertson remained optimistic Moody had the tools to return to the field.
"What I do know is that he went into the injury really fit. Medical procedures and surgeries these days are incredible, the technology that they use, the rehab.
"It's all there for him. They're reasonably positive that he will come back, and it's just a mindset thing. We're optimistic, that's all you can be."
The injury leaves a significant hole for the Crusaders and the All Blacks – "there is no one like Joe Moody pushing that scrum forward," said Robertson – but it also hands an opportunity to others like George Bower.
Bower would be the obvious replacement at the Crusaders while he will also be an option for Ian Foster ahead of the All Blacks' three-game series against Ireland in July, having joined the All Blacks' tour of Australia, the US and Europe last year alongside other fringe props Ethan de Groot and Karl Tu'inukuafe.
The 29-year-old prop will start this weekend for the Crusaders in the No 1 jersey against the Waratahs in Sydney, with second-year prop Tamaiti Williams providing cover on the bench.
Rookie Finlay Brewis, who has played just once for the Crusaders, provides more depth at loosehead.
Crusaders v Waratahs
Saturday, 7.05pm, Sydney
Crusaders: Will Jordan, Sevu Reece, Jack Goodhue, David Havili, Leicester Fainga'anuku, Fergus Burke, Bryn Hall, Cullen Grace, Tom Christie, Pablo Matera, Sam Whitelock, Zach Gallagher, Oli Jager, Codie Taylor (c), George Bower.
Reserves: Ricky Jackson, Tamaiti Williams, Fletcher Newell, Dominic Gardiner, Sione Havili Talitui, Te Toiroa Tahuriorangi, Simon Hickey, Dallas McLeod.
Waratahs: Alex Newsome, Mark Nawaqanitawase, Izaia Perese, Lalakai Foketi, Dylan Pietsch, Tane Edmed, Jake Gordon, Rahboni Warren-Vosayaco, Michael Hooper, Charlie Gamble, Hugh Sinclair, Jed Holloway, Harry Johnson-Holmes Mahe Vailanu, Angus Bell.
Reserves: TBC, Tetera Faulkner, Archer Holz, Geoff Cridge, Will Harris, Jack Grant, Ben Donaldson, James Ramm