Stefano Domenicali, Ferrari's team principal, fears that Fernando Alonso's Formula One world title hopes will be scuppered this weekend unless his team give the Spaniard a fighting chance in qualifying.

Alonso goes into the final grand prix of the year in Brazil trailing Sebastian Vettel by 13 points, and with the odds on him overhauling the Red Bull racer long.

Ferrari's Achilles heel is their one-lap pace on a Saturday: Alonso has qualified on the top two rows of the grid only once in the last nine races since claiming back-to-back pole positions at Silverstone and Hockenheim. Despite that, he has managed some astonishing results as has been on the podium in six of the past seven races to keep his championship hopes alive.

If the Spaniard is to pip Vettel in becoming the ninth driver to win three world titles, he will almost certainly have to at least get ahead of the German on the grid at Interlagos. "We always say it, but we need to improve our qualifying pace," said Domenicali, in light of Alonso qualifying a dismal ninth in Sunday's United States Grand Prix at the Circuit of The Americas. "Unfortunately, in Austin we had one of the worst qualifyings of our championship. We need to make sure Brazil is a different situation and it doesn't happen again otherwise it will be very difficult."

Arguably, Alonso's best hope of victory will be for Vettel to suffer a reliability issue that either compromises his grid position or affects him in the race.

"Pragmatically speaking, we know the result has to be better," added Domenicali. "We have to be in front of Sebastian and we need some drivers in the middle, without thinking of the worst-case scenario.

"This is the approach we need. We know it's not easy because he [Vettel] is driving very well and he has a very quick car. But that doesn't change what we have to do. We have to focus on our job and see what the outcome of the race is."

Following the inaugural race in the Texas capital there was a clear sense within Red Bull they had only done half a job after clinching their third consecutive constructors' crown but as far as team principal Christian Horner is concerned, there will be no let-up or thoughts of playing it conservatively in Sao Paulo. "We have to approach this race as we have the previous 19," assessed Horner. "We have to go there and get the best out of ourselves, the car, the strategy, the drivers and reliability. Anything can happen but it is good to be going there with a lead, and we go there determined to close the job off."