Dr Helmut Marko has revealed the extreme measures that Sergio Perez is taking in order to narrow the gap to team-mate Max Verstappen.
Verstappen has dominated the current campaign and won his third Formula 1 title in Qatar earlier this month.
Perez has been unable to keep up with the Dutchman and has endured a challenging season, leading to question marks over his future with the team.
While the deficit was still present over one lap at the Circuit of the Americas, Marko was more positive about Perez's performance compared to recent events.
"Perez qualified seventh for the sprint race, but the gap to Max Verstappen is relatively big at half a second,” Red Bull's Motorsport Advisor told Sky Sports Germany.
“However, if you get to the individual sectors, the difference is marginal. Half a tenth here, a tenth there.
"Checo needs to string the sectors together better, but an upward trend can be seen.
“So in the future, we can expect better performances from him."
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F1 drivers often spend a day in the simulator back in the team factories between races to prepare for an upcoming round.
While Perez is no exception, Marko has revealed that the Mexican requested several days in the simulator ahead of the weekend in the United States.
"Normally you sit in the simulator for one day in preparation, but he asked, of his own initiative, to spend three days in the simulator,” Marko said.
“That shows he is serious and wants to do everything he can to become competitive again.”