Pirelli boss Paul Hembery says that Ferrari's form this season is not related to Sebastian Vettel's tyre development work last year with the Italian manufacturer.
The German driver carried out over 2,000 kilometers of testing in 2016 with Pirelli's new-spec wider tyres, an extensive workload which surpassed by far the amount of miles racked up by Mercedes.
Toto Wolff recently admitted that the German outfit's lack of test running with Pirelli last season may have been a mistake.
But Hembery does not believe that the cause of Mercedes' recent difficulty in getting its tyres to operate in the correct temperature window is a lack of running last year.
"Yes, Sebastian did a lot of testing," Hembery told Formula1.com.
"It was very intense and he gave us a lot of feedback. We thank him for that. That is what we wanted: the top drivers giving us good feedback.
"But because he didn’t really know what he was testing - he was blind-testing - it might have helped him psychologically, but I doubt it helped practically."
Hembery also noted that Mercedes' tyre temperature issues, which appeared to subside last weekend in Montreal, were not present at every track.
"Actually Mercedes’ issue is linked a bit to certain circuits: in Barcelona they were fine - and in Silverstone and Spa they will be as well.
"It’s the lower-grip circuits where they’ve had a few more problems, but I am sure they will resolve any issues as we go through the season."
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Gallery: All the pictures from Montreal
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