Ferrari's decision to use scrubbed tyres in Q3 at Austin had no influence on its poor qualifying result, insist drivers Felipe Massa and Fernando Alonso.
Amid major tyre warm-up issues, the duo eschewed fresh rubber for the start of the pole shoot-out, but still struggled more than rivals and did not feature at the front.
But when asked by AUTOSPORT if Ferrari had made a tactical error Massa said he was confident the tactic had been correct.
"The last lap is the best," said Massa. "Normally it is a mistake if you don't use the tyres at the beginning [of their lives]. But it's not the case."
Alonso felt the tyres had not been a huge factor in Ferrari's struggle and that it was another case of it lacking qualifying pace relative to his title rival Sebastian Vettel's Red Bull, which claimed pole.
Asked about the scrubbed tyre choice, Alonso replied: "I think it was very similar. I think there was no difference.
"We decided to start with the scrubbed thinking it was not better or not worse. I don't think there was any problem with that.
"We were positions seventh and ninth in Abu Dhabi [qualifying]. The car is more or less the same. We are positions seventh and ninth in Austin. It's not surprising for us, to be honest."
Alonso stood by his post-qualifying declaration that he was certain he could beat Vettel on Sunday despite starting so far behind.
"We said yesterday after qualifying Red Bull will probably be one and two, we will probably be seventh or eighth and people will say it's all over," Alonso said.
"Then on Sunday we will show that we can score more points than Vettel. I don't know how, but we have this feeling inside."