Perez, who has been reported as the driver that will make way if Vettel is set to join the team, said he has no reason to worry by such a move thanks to how well himself and the team are performing so far this season.
Perez affirmed how the team is working well and are very competitive during race weekends, prompting no reason to think about making such a change in the team.
"I think it is, as I've said before, a matter of time," Perez said during Thursday's press conference.
"I feel really happy with the team. I believe in the project, I've been here for a while, and I can see how the team is going upwards. We all feel internally that everything is working well.
"We don't see the reason why we should change anything. I don't see any reason to change. I think we are enjoying a great season on-track, and things are working really well in the team.
"I don't expect any change. The feedback that I get from within the team is that we all want to continue and that's where my confidence comes from, and where we stay calm.
"It's a situation that is out of my hands, so I don't even bother at all. I focus on racing, enjoy it, and whatever happens, it's out of my hands, so I don't even give attention to it."
Bahrain International Circuit - Winter testing