Vettel and Alonso will start fourth and eighth respectively. Those positions make Alonso's task of overturning a 13-point deficit look tough.
But asked if the championship situation was the biggest thing on his mind, Vettel replied: "Not too much. I've just come out of qualifying knowing I could have done a little bit better. I'm keen to go back now and look at the data and see where I wasn't quick enough."
Vettel had been fastest in Q2 before making a mistake on his first Q3 lap and then missing pole by 0.302 seconds on his second. His team-mate Mark Webber took third behind the McLarens.
"Q3 was not 100 per cent perfect. Q2 was quite good for us," said Vettel.
"The first run in Q3 was not good for me as I did a mistake going into Turn 4.
"The second run I was pretty happy with it but it wasn't quick enough."
But he remains confident he will be a factor at the front in the race.
"Obviously Mark was a bit quicker, but I think we are in good shape and we've competitive all weekend," Vettel said.
Alonso's team-mate Felipe Massa starts just one place behind Vettel in fifth, but the Red Bull insisted this did not bother him in the slightest.
"There are always going to be cars around you," Vettel said. "It would be boring if it were just me on the grid. I think that's pretty normal. We have mirrors on the car but we try not to use them too much."
Alonso described his eighth place on the Brazilian Grand Prix grid as "no surprise" and is still confident he can finish on the podium.
"It's not a surprise because we started seventh in Abu Dhabi, ninth in the USA, and eighth here. So it's more or less as expected," said Alonso.
"We'll try to repeat our performance on Sunday and reach the podium like Abu Dhabi and Austin.
"We need some strange circumstances, we need a chaotic race in a way, rain or something, let's hope we see something like that."
He also denied that Ferrari had gone for a fully wet set-up in qualifying in anticipation of Sunday rain.
"We ran with maximum downforce in the dry so obviously it is the same in the wet, so no big changes," Alonso insisted.
"I don't think anyone gambled today for a wet set-up because there is minimal changes."