The Blaugrana coach is determined to prevent the 23-year-old from causing an upset, after his side was held to a 1-1 draw in the first round of the tournament.
"Banega is a fantastic player. We'll have to be plugged into the game to render him ineffective," Guardiola said in a press conference.
"If they are behind us, Banega won't be as big of an issue. If we're behind them, Banega will be key."
Guardiola continued to express his team's desire to clinch another trophy, and are fully motivated to reach the finals.
"I know that we've won a lot of titles, but these players want to reach another final. The cup final is one of the most beautiful ones. For this reason, the match this Wednesday is key. It's not everyday that you qualify for a final."