Sevilla welcome United to the Sanchez Pizjuan Stadium on Wednesday evening and Spain international Navas, who spent four seasons with the Citizens, is eager to help down the Red Devils and bring about some smiles in the blue half of Manchester.
"For us, it's all about getting through to the next round," the 33-year-old told The Mirror. "But I know it would be nice for some of the friends I've got back in Manchester if we did manage to pull it off and knock United out.
"United were always our great rivals when I was at City, and we played some really important games against them.
"We're a great side and we can achieve things. We know we'll have to be at our maximum level and concentrated throughout both games because, at any moment, a top team like United can finish the tie."