Hembery is now stepping up the pressure on the teams to agree to some hot weather winter testing in the Middle East for early 2014.
May 14 (GMM) Pirelli is speeding up a scheduled change of tack for its 2013 tyres.
Following harsh criticism both inside and outside the paddock amid the Barcelona four-stoppers, Paul Hembery announced that changes would be made for Silverstone.
But on Tuesday, the Italian marque's motor sport director said the changes will now make their debut one race earlier, in Canada, which is the race after next weekend's Monaco Grand Prix.
"Some structural changes," Hembery tweeted, "combining elements (of the) 2012 and 2013 products."
Auto Motor und Sport correspondent Michael Schmidt said the 2012 tyre construction will be revived, although the changes to the actual compounds will be minor "so as not to upset Ferrari and Lotus too much".
"The purpose of the change is that the compounds do not heat up as much, especially at the rear," Hembery is quoted as saying.
The change will have an aerodynamic impact on the cars, as the 2012 construction did not deform as much in the corners.
Hembery explained: "It may well be that we keep the compounds as we used in Barcelona. If anything, the changes will be minor.
"We want to stay on the aggressive side, to keep the races exciting and not punish the teams who are doing a good job with these tyres."
Hembery is now stepping up the pressure on the teams to agree to some hot weather winter testing in the Middle East for early 2014, and also for an up-to-date test car.
"The Renault that we have is three years old and four seconds slower than today's cars," he said.
"Already this year we're seeing as much rear downforce as in 2011 with the blown diffusers.
"We cannot develop tyres like this," added Hembery.