Team boss Mike Krack has swerved away from Fernando Alonso's suspicion that the mid-season tyre construction change explains Aston Martin's recent slump.
Alonso, who turns 42 on Saturday, repeated his theory in the Spa-Francorchamps paddock on Thursday.
"The rules changed in the middle of the year and we haven't properly adapted to the new tyres yet. So we need to do better," said the Spaniard.
"I don't think it's a particular characteristic of these tyres, it's just that we are slower with them.
"I don't have all the information that Pirelli has, but I'm not a fan of changing the tyres in the middle of a season. But it's been several years of doing this - with the flexibility of the wings, the exhausts.
"It shouldn't be like that, because if a team has found something better they should be able to end the year like that. And if it wasn't legal before then they couldn't have run the first 10 races with those parts," Alonso added.
Team boss Krack, however, is more diplomatic about not pointing the fingers of blame too squarely at Formula 1's rule-makers and Pirelli.
"That would be an easy excuse, wouldn't it?" said the German.
"We do see that there's a little bit of a difference with these tyres, but they were brought in for safety. So from that standpoint, everybody has to use them and it's the same for everybody.
"Basically, I don't think we should use this argument as an excuse for our competitiveness, because these are the same tyres we have to use in the future. So it's more about learning as much as possible about them and moving on," Krack added.
Aston Martin has introduced a new floor this weekend in Belgium.
"With the sprint, the weather and little practice time, it's a bad combination for us here," Krack said.
"But what should we do? We expect an improvement, so we're bringing the new parts."
Krack thinks the new tyres are just part of the "incredibly complex" technical situation for teams now in Formula 1's new ground effect era.
"It's not enough anymore to just add downforce," he said. "Because you can get bouncing or the balance no longer works."
He admits that Aston Martin made "some wrong decisions" recently "in terms of development and setup".
"Some of our old strengths are now our weaknesses," said Krack.
