Robertson said over the last few years the Blues had pushed the Crusaders all the way and in a couple of games the Crusaders had to come from behind to win.
"These are tough games, they are all earned. It's not a gimme at all. They're tough and physical battles and the boys have come off and know they've been in some fight and it'll be no different on Friday," he said.
After their 15-25 loss to the Chiefs, the game is the second of an early season tripleheader of local derbies and Robertson was keen the side ensure they build on momentum when they secure it, especially in the second half, where the Chiefs had sealed the game last week.
Robertson said the Crusaders hadn't been beaten on effort and a couple of calls had not gone their way. The Chiefs were a good side.
"We had plenty of opportunities, it would have been nice to have a couple of calls go our way and Warren [Gatland] said the same thing. A little bit of luck goes with the footy. We got a couple of calls the other way but it was just at the right time and when we had that little bit of momentum we didn't quite get them," he said.
"It was a hell of a game and it is what Super Rugby needs, that quality of footy and that rivalry," he said.
There were a couple of key moments at breakdowns which the Chiefs managed to dominate and that was the game, he said. It showed how tight local derbies could be.
"We still created a lot of opportunities. We've got a great backline and we just want them to play."
First five-eighths Richie Mo'unga was good to go after fully recovering from a knock in the first round, he said.
David Havili stood in for Mo'unga last week, starting at first five-eighths for the first time for the side. He set up the two Crusaders tries, his kicking game was good, he was tough and composed and it showed the All Blacks selectors he was capable of playing any position bar halfback in the backline.
No 8 Whetukamokamo Douglas had suffered two broken fingers and just how long he would be out of action was uncertain. That has resulted in Cullen Grace being handed a start at lock with Tom Sanders moving to No 8.
Robertson regarded him as an exceptional talent who was building nicely.
"It's his opportunity. We were looking forward to giving him a start. It's probably come a little bit earlier than we expected but he's good to go," he said.
Grace offered the side a blindside flanker who could also play lock, something they hadn't had for a while.
Penalties had been an issue in the first two games, the Crusaders were second highest among all teams for penalty concessions. They had worked on that during the week and had also spoken with referees on the matter. On some of their penalties they were told they just needed to be better in what they were doing, he said.