Red Bull are poised to take measures to ensure Sebastian Vettel's bid for a third consecutive Formula One world championship is not wrecked by unreliability in Sunday's title showdown in Sao Paulo.
Although Vettel extended his lead over rival Fernando Alonso to 13 points following a second-place finish in the United States Grand Prix, team-mate Mark Webber retired with an alternator failure.
As Vettel was forced out of both the European and Italian races with the same issue - the former when leading - there is now real concern within the team he could be pipped at the post by Alonso in Brazil due to another alternator issue, and team principal Christian Horner said: "It's just a worry, full stop."
Engine suppliers Renault recently developed a new specification of the device that was run successfully in Austin by two of their other customers, Lotus and Caterham.
Red Bull, however, opted for the older-spec model, a case of better the devil you know, only to suffer with Webber retiring.
For Interlagos, it appears certain Red Bull will now switch to the new spec alternator.
Horner continued: "Unfortunately it is the third alternator (failure) we've had and there have been others in other cars.
"The new version has raced on other engine cycles and hopefully that's what we'll have for Brazil."
There are no guarantees, however, the new model will prove any more reliable as Red Bull's chief technical officer Adrian Newey said: "The component is not a new component.
"It has been on the Renault engine since about 2005 and it has been failing since 2005 as well."