The Citizens hold a 4-0 advantage after running riot in Switzerland three weeks ago.
But Ederson believes City must keep winning games.
"We are focused on our next challenge now, the Champions League, but we can't feel comfortable at all, we must be always careful and doubtful.
"Despite the result away, this game is extremely important. We are going to start the game focused and aim to win.
"For us the key is to keep on working hard to be focus, like we have been doing this season, that's how we get to win games. It won't be different this time."