"We went to Montreal expecting our car to be really strong and we left seeing that we haven't been where we thought we should be," he admits.
"You need to find the right balance between pushing the development very hard and at the same time keeping reliability," he continues. "This team has been extremely strong in the past at keeping reliability at a high level. That is not something that worries me.
"It is more that we have seen Ferrari has had the stronger car here. Stronger in qualifying, stronger in the race. At no point did we have a real chance of fighting for the win.
"There's not really a pattern," says the Austrian. "Before, on some tracks we were dominant and on others we struggled but somehow this year the margins have become so tight.
"If we look at the fastest lap of the race, it is five cars within a tenth of a second. That is why this year's championship is going to be decided by who makes the least mistakes and brings the best development onto the power unit on every single weekend. That is the new reality.
"It's a three-way fight," he concludes. "Six cars can win races. You can't take anything for granted. You can't go to Montreal and think it is going to be a walk in the park. That's the kind of wake-up call you get."