The Brazil international says the Ligue 1 champions are already getting used to the new coach's demands and feels they have improved since his appointment
Emery replaced Laurent Blanc as head coach in June, having guided Sevilla to a third Europa League title in a row, with PSG aiming to add European glory to their unrivalled domestic dominance.
A 3-1 International Champions Cup victory over Inter showed signs that PSG are already beginning to develop under their new boss.
And Lucas feels they could benefit from a tougher approach and working harder without the ball in the coming campaign - qualities he suggests they lacked under Blanc.
"I think that we've started to do things that the new coach asks of us," he was quoted as saying by L'Equipe . "Our team is a bit different this season. We're a bit tougher.
"We played a good match, I'm happy.
"Everyone wants to see a good PSG this season. We're working hard tactically and positionally. It's very intense. You saw that against Inter.
"As soon as we lose the ball, we try to get it back as soon as possible. That wasn't the case before, and it was a problem."