The Andalusians are looking to overturn a 2-1 deficit against los Rojiblancos, as they attempt to replicate their 2010 cup success.
And the former Valencia boss is hoping for a positive reaction from his players, however, he says they must remain cool under pressure.
“We're still motivated on every level, but we need to make sure that we don't become over-excited,” Emery told Marca.
“You need to use your bite when it's the right time, not just for the sake of it.”
Sevilla lie 12th in La Liga and the Copa del Rey represents their best chance of silverware this season.
Atletico, meanwhile, were knocked out of the Europa League last week by Rubin Kazan, and sit in second place in the Spanish Primera Division.
Emery also revealed the club's president Jose Maria Del Nido’s desire for a victory in the competition.
He added: "From the first day that I arrived he's talked with me about the cup, and he brings the subject up on a daily basis. He's always optimistic and hopeful about it and I've pass this on to the players."