Both Ferraris ran the slower medium Pirellis in Q3, leaving Felipe Massa and Alonso back on row four of the grid.
But Alonso said Ferrari's qualifying pace deficit was now small and it had simply tried to choose the best race strategy.
"I think we did a step forward in this race," he said. "We are more competitive than we were at Silverstone, where we were 1.5 seconds off the pace, in practice and Q1 and Q2. That was not the case today.
"So definitely the team did a step forward and we've come back to a more level of competitiveness. We need to improve, yes. No questions about that.
"We were not the quickest before, especially on Saturdays, we are not the quickest now obviously but we are more confident and optimistic for tomorrow because the car is performing more in a normal way."
He conceded that Ferrari did feel the times in the pole battle were out of reach.
"When they pushed in Q3, we saw 1m29.3s, which is for us a little bit too fast," Alonso said.
"So more or less as expected, we knew with the soft maybe we could qualify fifth or sixth, with the medium seventh or eighth.
"And in terms of strategies, it is not clear which will be best. Tomorrow we'll find out.
"Whatever tyre you have, if you are fast you will be on the podium or win the race, if you are not fast, with whatever the tyre, you will not be in the points. So it is about the pace tomorrow - not the tyres or the strategy."
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