Sainz went quickest in Friday afternoon's one-hour FP2 session, his 1m21.355s just 0.019s quicker than McLaren's Lando Norris.
The first Red Bull of Sergio Perez was 0.185s behind in third, followed by the second McLaren of Oscar Piastri and Perez' team-mate Max Verstappen.
But when asked if Ferrari's tifosi can start dreaming after the Scuderia's impressive practice performance, Sainz pointed out Red Bull's long-run pace is still far superior.
"Dreaming is for free, no? This is one of my favourite sayings. I think we can all dream and it's for free, no one can it take away from us.
"But being realistic, also looking at our race pace, that's when we start to see the true pace of the Red Bull again.
"They were clearly again three-tenths of a second ahead in race pace and over 50 laps that's a lot of lap time."
Source: Autosport