The Canaries are three points clear of the Black Cats and nine points above the drop zone going into the clash at the Stadium of Light.
"There's going to be twists and turns between now and the end of the season," Turner said. "We play Sunderland, who are below us, and then we play Wigan, who are in the bottom three at the moment.
"It's an important game for both clubs and we'll be fully focused going into it," said Turner. "It would be nice to keep that cushion after the game.
"We've got big games coming up and I'm sure if we can get through those games in a decent position then we'll be confident."