Mercedes boss Toto Wolff lamented the "enormous" loss of performance around Imola due to the 2021 Formula 1 rule changes.

The reigning champions have been among the hardest hit by the new floor regulations, which they have even suggested were specifically aimed at slowing them down.

And though Lewis Hamilton claimed his 99th career pole for the Emilia Romagna Grand Prix in qualifying, the Austrian doesn't believe it was on pure pace.

“The pole was a surprise because at the moment we do not have the quickest car,” said Wolff via Motorsport Week, with both Red Bulls less than a tenth behind.

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“It was so close and Max [Verstappen], without the mistake, would have been solid on pole, maybe not as much as Bahrain but he would have been there."

Hamilton's lap time, however, was eight-tenths slower than Valtteri Bottas' pole time around Imola last November

“The loss compared to last year is just enormous – we were six tenths ahead [in 2020] and now we are two tenths behind," Toto suggested.

“We need to scratch our heads and just try to find the performance.

“It’s a quicker car than in Bahrain, I think we have got the car in a better balance window, that’s the main reason for the improvement.

“We had some drivability concerns in Bahrain and we are sorting that out – slowly we are getting there.”

Looking ahead to race day, the Mercedes chief isn't too comfortable about Hamilton's prospects of victory, particularly with teammate Valtteri Bottas only eighth.

“It’s a big advantage for them because not only two Red Bulls behind but [Sergio] Perez is starting on Soft tyres so they can do two different strategies,” commented Wolff.

“Valtteri has to make his way through the soft runners, which he will and can, but I think we are a little bit on the backfoot.”