While his team-mate Valtteri Bottas was just 0.045 seconds shy of pole position as he qualified third, Hamilton was only 14th in Q2.
“We couldn't get it (the set-up) right on Lewis's car, therefore he had a disastrous qualifying,” Lauda told Sky Sports after the session.
“Bottas's car was better, very close to the second place. With him we're happy, with Lewis, not at all.
“We have to analyse it, check carefully what the difference is between the two cars and why the whole set-up worked on one car and not on the other.”
Hamilton had to save big moments at Massenet and Casino Square on separate flying laps in Q2, and then aborted his final lap of the segment when Stoffel Vandoorne brought out yellow flags by crashing his McLaren at the Swimming Pool.
Asked how his qualifying without the Vandoorne incident, Hamilton told Sky Sports: “I think I would have struggled.
“That lap may have just got me into the top 10, and then I probably would have struggled to be in the top five with the pace that I had, with whatever issue I was having in the car.
“But it's great to see Valtteri was able to extract the performance of the car, it shows we're not terrible here.
“We'll just have to figure out why I couldn't be up there with him.”
Hamilton admitted he was at a loss over his lack of pace.
“I don't know, I've not spoken to the guys so I can't really pinpoint it at the moment,” he said.
“But it's an odd feeling, that's for sure.”
Responding to the suggestion that the problems from Thursday – when Mercedes languished down the order in second practice, struggling to switch on the tyres – were not solved, Hamilton said: “Clearly not. That's why I'm 14th.”