Sergio Perez could be given one of the best opportunities of his career to win his home race, having already achieved wins at Monaco and Singapore this year.
The RB18 is also on a string of race wins after teammate Max Verstappen has dominated the second half of the season so far.
But after a "tricky day" finishing third-fastest behind Ferrari in FP1 and fifth quickest in FP2 during the Pirelli tyre test, Perez expects qualifying to be more challenging with Mercedes also showing strong pace.
"It was a tricky day to get a read on things, as is typical in Mexico with the altitude, everything is floating around," he told media.
"It is very easy to make mistakes in these conditions, so overall I think we had an okay day.
"I think we got up to speed fairly quickly and got into a rhythm, so it should hopefully be quite straightforward tomorrow."
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Ferrari and Mercedes will make qualifying difficult
Perez's best finish at the Mexican Grand Prix was third, achieved in last year's event, but he expects Ferrari and Mercedes to put up a "tough battle" in qualifying given the close margins in practice.
The Mercedes drivers spoke of their optimism after the practice sessions, which has left the Mexican wary as he looks to take a first win in front of his home crowd.
"The tyre test means you basically lose FP2, but that’s how it is for everyone and in FP1 we had a good pace and we seemed to be competitive.
"Ferrari look strong, as do Mercedes, so it is going to be a tough battle tomorrow in qualifying."
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