The Andalucians progressed on away goals after their two-legged tie against holders Barca finished 2-2 last week and now play their quarter-final first leg at La Liga rivals Deportivo La Coruna on Wednesday.
"We think we have to be 3-0 up after 20 minutes, like Barca, but we need to play with more calm," Argentine Duscher told the club's website.
"We have had matches where we created a lot of chances and haven't scored and we have to have more patience. After knocking out a great team like Barca it was clear we now have the responsibility to get as far as possible."
Sevilla have slipped to sixth in La Liga after four straight defeats and have not won at home in the league since they beat Villarreal 3-2 in early November.
FABIANO COMEBACK
However, with Barca, Real Madrid and Valencia out, they have a good chance of repeating their 2007 Cup triumph and have been boosted by the news Brazil striker Luis Fabiano is likely to make his comeback from injury against Depor.
French defender Abdoulay Konko, though, damaged adductor muscles in Saturday's 4-0 La Liga defeat at Barca and is out for at least four weeks.
Improving Atletico Madrid host second division Celta Vigo, the only side left from outside the top flight, in their first leg at the Calderon on Thursday.
Atletico stormed back from a 3-0 first-leg deficit in the previous round against second-tier Recreativo Huelva to go through 5-4 on aggregate and followed up with a 3-2 home win over Sporting Gijon in La Liga on Sunday.
Uruguay striker Diego Forlan injured his ankle against Sporting and is doubtful for the Celta game.
In other first-leg ties in-form Real Mallorca, who have brushed aside serious financial problems to climb to fourth in La Liga, host Getafe on Wednesday and Osasuna play at Racing Santander on Thursday.
