The Suzukis of Aleix Espargaro and Maverick Vinales topped the timesheets in Saturday's qualifying, with Lorenzo posting the third fastest time ahead of Marquez in fourth.
Lorenzo comes into the race on the back of three consecutive victories, and Marquez believes that he remains the man to beat.
"I think that Jorge has the best pace, although we shouldn't forget about Valentino and also Dani," explained the Repsol Honda rider.
"They are all dangerous, but we will try to give 100% in front of the home fans in order to be as close as possible to them. We'll see if we can keep with them when we get to the end of the race."
Of his own performance, Marquez admitted that he had hoped to be in the top three.
"[It] went fairly well," he said of Saturday's running. "To be honest, the objective was to get onto the front row; it's a shame that in the end it eluded us, but Aleix and Maverick were very fast."
After claiming back-to-back World Championships in his first two seasons in MotoGP, Marquez has struggled in the current campaign, registering just one race victory in six attempts while twice failing to finish.