Valtteri Bottas looks set to be shuffled into de-facto 'number two' status for the remaining eight grands prix of 2017.
Bottas, however, thinks that he is still in the hunt.
"There are still eight races and a lot of points left on the table," he is quoted as saying by Auto Motor und Sport.
"Lewis and Sebastian have had no failures yet, and I don't wish that on anybody - it's just a fact. Something can always happen.
"It's up to me. I just have to be on pole position and then beat my opponents."
When asked about the spectre of 'team orders' in relation to Hamilton's push to keep closing the 13-point gap to Vettel, Bottas said: "I don't think too much about it because I don't want it to affect me negatively.
"It is clear that from a certain point in the season the team must clearly put everything on one driver. But to me it seems a little bit early now."
From Mercedes's point of view, however, the issue of a driver hierarchy is at least ripe to be thought about.
"You can only beat an opponent like Ferrari when everything fits," boss Toto Wolff said.
"We do want to keep ourselves open for all the options as long as possible, and we also know that there is no manual for dealing with these problems.
"Ferrari has the luxury of one driver being clearly ahead of the other, so for now we will decide on a race by race basis.
"Let's see after Monza. It is a circuit that is good for us, but we saw at Spa that Ferrari has made progress."
Team chairman and F1 legend Niki Lauda, however, thinks the time has now come for Hamilton to get full 'number 1' backing.
"This giving away of points must stop now," he told RTL, clearly referring to Hungary when Hamilton pulled over for Bottas to honour a policy of driver equality.
"I was champion by half a point, so I know exactly how important every single point is when you count them in the end.
"I know exactly what we need to do. Bottas did not have a strong weekend at Spa so it is already clear that Lewis has a better chance for the championship.
"If Lewis had not given away those three points in Budapest, he would now be only four points behind Vettel."
Mercedes lead the way to second-placed Ferrari by 44 points ahead of the Italian Grand Prix.