Dos Santos is one of the few experienced players in Mexico's young and depleted squad and was by far their most dangerous threat in the 2-1 defeat by Chile in their opening Group C match.
He is expected to lead Mexico's attack against Peru in Friday's clash and Vilches is likely to have the job of stopping him.
"I'll try to stick close to him," Vilches said after his side's final training session.
"There are players who when they're given space can turn a match around and Giovani is one of them. The idea is that when he gets the ball with his back to goal, we get close to him and we don't allow him to turn and see what's in front of him."
Both sides need a win to keep alive their hopes of reaching the knock-out stages of the competition. Peru drew their first match of the tournament with Uruguay.
Mexico, who are here by invitation, are fielding what is effectively an under-22 squad with only a few senior players, and sent eight players home on the eve of the tournament due to a disciplinary scandal.
