The Spanish club go into the game following a 1-0 defeat at relegation-threatened Real Zaragoza, but Juanfran does not want his team-mates to focus on that and target a win in Europe instead.
A 6-1 aggregate victory over Turkish side Besiktas set up the clash with Hannover and Juanfran wants to keep progressing.
He said: "Since the Zaragoza game finished I've spoken will all my team-mates and the most important thing is that we win on Thursday.
"I want to make an appeal to our fans for them to fill the stadium and give us their support. We want to get through this tie and we want to reach the final.
"For this we need to take it game by game and start by winning on Thursday. I hope the fans are behind us and we will give it everything on the pitch."
Former Spain Under-21 international Juanfran also believes a good performance can yield a positive result against their German opponents.
"The coach (Diego Simeone) has not left any details to chance, we know their style of play and we are going to play our game, with our fans," he said.
"If we play well and do things well, we will have a good chance of winning."
Hannover captain Steven Cherundolo admitted Atletico play nice football but that does not mean his side are necessarily going to be eliminated.
He said: "Basically, play emphasises all of the Spanish teams, they can combine all the great skills and play nice football, but they're not unbeatable."
Hannover beat Standard Liege to reach this stage and 33-year-old Cherundolo feels that can be a building block ahead of the tie.
"I'm sure our coaching staff have done their homework and will prepare our team as in previous rounds," he said.
"We must build on the power that we have shown at home against Liege, I am very excited and optimistic."