Toto Wolff has described Mercedes’ 2017 car as a "diva".
A ’diva’, of course, is a talented yet temperamental individual, and so it proved at Monaco where Lewis Hamilton struggled to master the silver car at Monaco.
"I believe we have shown so far that we have a fast car," Mercedes boss Wolff is quoted by German media.
"But we also seem to have a bit of a diva, as far as bringing the tyres into the optimum window. So we have to do better on that."
He denied that the problem at Monaco is simply the difference in wheelbase length between the long Mercedes and the comparatively ’short’ Ferrari.
"If we had been the fastest, everyone would have said that the long wheelbase is no problem. Now they’re saying it’s to blame," said Wolff.
Team chairman Niki Lauda says he also sees a more fundamental handling issue with the 2017 Mercedes.
"I have talked to Lewis at length," the F1 legend told Bild am Sonntag.
"Our car is fast but restless. Driving fast requires more work than driving the perfectly-tuned Ferrari," he added.
And so on Sunday, on the tight Monaco streets, Hamilton faces a tough task to limit the damage to his championship rival Sebastian Vettel.
"Overtaking is impossible here," Lauda is quoted by Kolner Express newspaper. "Lewis needs to drive like a madman."