Norris in need of big Brazil points-swing as Ferrari set sights on title
The McLaren driver arrives at Sao Paulo's atmospheric Interlagos circuit 47 points behind Red Bull's triple world champion with four rounds to go and a maximum 120 points available.
Verstappen is the clear title favourite, with Norris still needing to outscore his rival by 12 points on average in every round, but there is plenty of scope for events to conspire against him.
Ferrari are on the rise, on the brink of three wins in a row in the Americas while chasing a first constructors' title since 2008, and that could help Norris if he were to win with Carlos Sainz and Charles Leclerc pushing Verstappen down the order.
The Italians, only 29 points behind leaders McLaren after two big-scoring weekends in Texas and Mexico, will not be easy to beat, however.
"I think we both believe it (the title) is possible and we are actually talking about it more and more often now," said Sainz, the winner from pole in Mexico City.
Verstappen's two 10-second penalties in Mexico, with the stewards clamping down on moves that force others wide, could also have a significant effect on how the title contenders go racing from now on.
Brazil is the fifth of six sprint weekends on the calendar, putting an extra eight points in play from Saturday's 100km race, and Verstappen has won all the other four this season.
He also won the sprint and Sunday's main grand prix in Brazil last year, when Red Bull were dominant, with Norris second in both.
"Mexico was a race to forget but we know that we can do better and are working hard to figure out what went wrong so we can improve our form for the final few races," said Verstappen, who started second but finished sixth last Sunday.
There is also the possibility of a grid penalty for an engine change, yet to be confirmed, but that would be less of a problem for Verstappen at Interlagos where overtaking is comparatively easy.
Under-performing team mate Sergio Perez will also be in the spotlight, with Red Bull boss Christian Horner refusing to confirm the Mexican would remain on the starting grid after Interlagos following his dismal run of form.
"Mexico was the most disappointing weekend of my season," said Perez.
"I wanted to have a special weekend and as a team we didn’t walk away with what we deserved. We need more from my car to start to compete more and that’s got to be the aim before Brazil."
Mercedes could also be in the mix, with honorary Brazilian Lewis Hamilton now a crowd favourite in the birthplace of the seven-time world champion's boyhood idol Ayrton Senna, who died at Imola 30 years ago.
"We know it will be difficult to challenge the Ferraris and the McLarens who have looked strong in recent races," said team boss Toto Wolff.
"We will still be working hard to do so though and will see where our relative performance is over the weekend."
