After three years of dominating Formula One, Toto Wolff believes Mercedes is now the underdog in this year's title fight.
Ferrari overtook Mercedes in the constructors' championship at the Monaco Grand Prix on Sunday after taking its first one-two victory in seven years. The two teams have taken three wins each so far this year, but Ferrari has been the more consistent with lead driver Sebastian Vettel finishing in the top two at all six rounds.
In Monaco, Mercedes struggled to get the most from its tyres, with Lewis Hamilton qualifying 13th before recovering to seventh in the race. The result leaves him 25 points off Vettel in the drivers' standings and Mercedes with an awful lot of head scratching ahead of the Canadian Grand Prix in two weeks.
"I like the notion of underdog," Wolff said. "Because the underdog is the one people obviously want to see win. But as matter of fact, I think we have been since the beginning of the season."
Mercedes struggles stem from difficulties keeping the tyres at the optimum temperature to extract maximum performance. In Monaco, both drivers complained about the tyres going in and out of the "temperature window" and the difficulties of getting both front and rears performing at the same time.
"We have been dropping in and out of the tyre [performance] window," Wolff added. "We never had two drivers or two cars within that window.
"We have seen an exceptional performance of Valtteri in Sochi which we were not able to replicate on Lewis' car, we have seen an exceptional performance of Lewis in Barcelona and that inconsistency has been following through the season.
"And on the opposite side, Ferrari put the car on the track in Barcelona and were quick from the get go so yes we are the underdog, yes we need to catch up. This is the reality of it at the moment."
Wolff says Mercedes are not alone in struggling with the tyres, but praised Ferrari's ability to make them work in all conditions.
"At the end how the car and chassis interacts with the tyres is a very complex topic, there's many dozens of factors which make it perform or not. This is not about seeking excuses as others are able to extract the performance of the tyres that we do not.
"You've seen from some of our competitors like Red Bull who have been far out of the window like 1.5s off the pace but back in the race they were performing well. It's a problem which seems to hit everybody but not Ferrari so credit to them, all credit to them they have a solid car on the track which can seem to cope with the tyres."