Perez has been consistently in the spotlight over the past few months due to a run of performances that have belied the pace advantage of the car over the rest of the field, and which has carried Max Verstappen to a remarkable new F1 record.
Since beating polesitter Perez from ninth on the grid in Miami, Verstappen has won 15 of the last 16 races. In contrast, the Mexican has managed just five podiums over that period, with none in his last six.
On home soil, Perez fanned the rumour flames by crashing out at the first corner as he made a bid for the lead.
Over the São Paulo weekend, however, there were signs Perez was finally rediscovering his pace, finishing third in the sprint before losing out to Aston Martin's Fernando Alonso for the final place on the podium following a remarkable duel between the two in the closing stages.
“I thought he drove brilliantly well,” assessed Horner. “He had a little bit of a wobble at (turn) two, which allowed Fernando, who was very quick on the straights, to have a go at him.
“He did his best to hang on to it, but for Checo to outscore Lewis (Hamilton) by 12 points, it was a very strong weekend for him, with third (in the sprint), and fourth from ninth on the grid.
“That result was important for his confidence. That was the Checo we know, and what he's capable of, and that'll give him just the boost he needs going into another street track (Las Vegas). He has always performed well on those.”
As to the change in Perez, Horner has revealed the 33-year-old was now simply “focusing more on the basics”.
It could be argued Perez has been affected by the constant speculation regarding his future, taking questions on the matter at almost every grand prix of late as the results have failed to materialise.
As to how the gossip has impacted upon him, Horner said: “I'm sure it does.
“But I think what we've seen with him, one of his strengths, is that he has a very thick skin, and many times he's picked himself up, brushed himself down and got back up again.”
Horner seemingly did not aid Perez's cause by stating after his driver's crash in Mexico that it was the “intention” of the team to retain Perez for next season, allowing him to see out his contract.
As to the meaning behind the word, Horner delivered an unambiguous statement.
“I am absolutely confident and clear that Checo will be our driver next year,” said Horner. “Now if he was injured or something like that, then there are circumstances beyond your control.
“But the clear plan, and therefore the clear intention, is that he will continue. We're planning to continue.