Fernando Alonso said it was "sad" that Ferrari had not been able to reduce their performance deficit at the Singapore Grand Prix.
Ferrari brought a number of upgrades for this race but Alonso qualified seventh, 1.1 seconds slower than title rival Sebastian Vettel, who is on pole.
"We came here and we are maybe fourth fastest team," Alonso said.
"It's sad news for us, but [there is] nothing we can do apart from preparing a perfect race."
Ferrari had hoped the new car parts would close the performance gap to Red Bull but if anything it seems to have grown.
Alonso pointed out that he was 0.8secs off the pace at the Hungarian Grand Prix, a track with similar demands to Singapore, and 1.1secs behind this weekend.
"We are happy with the work the factory has done," he said. "They work 24 hours [a day] non-stop.
"It's true we are not in the position we wanted in terms of performance but it's not because [the factory] didn't try the maximum. We are happy with the work they have done - day and night to bring new parts to the races.
"We brought here the front wing and other new parts [including a rear wing and diffuser] and they are working fine.
"They gave us around 0.1secs which was the expected time gain so everything was good. But our opponents are not watching the TV obviously between grands prix and they are also improving."
He admitted he needed to be "realistic" about his chances of closing his 53-point deficit to Vettel in the championship, but added: "We will see if we can improve in the next circuits, even if I doubt it because all July we were around 0.8secs slower than our competitors and here were are 1.1secs.
"It's not as if in [the next races in] Korea and Japan we will be in pole position by a magic wand.
"The situation was like this also last year and we arrived [at the final race] in Brazil with possibilities when we were clearly slower than our competitors, so we will not lose the hope and we will try until the end."
He said he was still optimistic of a strong race on Sunday.
"Last year was a good example," he said. "We were not quick enough. I think I started fifth or sixth and had a terrible start, [Paul] Di Resta passed me, I arrived in Turn One in sixth or seventh position. And we were on the podium.
"It depends on the situation in the race. It depends how the pace is tomorrow, how we make the tyres survive in the long runs and what is our opponents' luck - unfortunately we are in those hands as well.
"We were out of the podium until Lewis (Hamilton, who was leading) had the gearbox problem and we took the podium position.
"Tomorrow you will never know. It is a so-so weekend, [we are] not so fast and not in good positions, but tomorrow maybe we are third, fourth, fifth and our main opponent does not finish the race. So we need to wait for tomorrow and keep pushing."