Perez had one of his best qualifying sessions of recent months relative to team-mate Max Verstappen, finishing Q3 just 0.160s behind the world champion as the pair lined up third and fifth.
However the two Red Bulls were split by the AlphaTauri of Ricciardo, who was quick throughout qualifying, taking fourth, fifth and fourth across the three sessions.
It was the first time since he returned to the grid this year that Ricciardo had genuinely signalled that he could ultimately replace Perez, but the current incumbent downplayed the suggestion.
“Daniel did a tremendous lap,” he said. “I don't think it's just Daniel who wants my seat.
“Let's say there are a lot of other drivers who want to be in that seat. And it's great. If it's what they deserve, then I'm happy for them.”
Perez conceded he hadn’t expected the AlphaTauri to be so competitive in Mexico.
"Yeah, and not the Ferrari as well,” he said, referencing the Maranello team’s unexpected front-row lockout.
“But it is what it is. I think our progression in Q3 wasn't great, we ended up losing a set [of soft tyres] that potentially we didn't need to.
“You only know that after qualifying, and I think that really hurt us, the progression we had in Q3.
“When you are talking about a tenth and a half to two-tenths, it would have changed our life completely. So it is what it is.”
He added: “Especially during qualifying it ramped up a bit, the temperature, which did change, as I say, 3-4 degrees of track temp.
“In any other place you don't feel that, but in Mexico, it changes the balance quite a lot, because you are so much on the edge, and always sliding around.”
Perez said that he made progress over the US GP weekend, and that has continued at his home event.
"We already made the progress in Austin,” he said. “We are making progress here. So yeah, I think we are on a good level with the car.
“Obviously, this track is really difficult, every single set of tyres that I had today performed differently. So it is a track that is really difficult to get the most out of it.”
Expanding on his form he said: "I don't want to go too much in detail. But certainly, I'll say that we got lost a few weekends with the set-up.
“We took a reset. I think for us it's looking better now, we're starting the set-ups a lot closer, and it was diverging through the weekends on things that we want to achieve differently.”
