Wagner also insists they cannot be obsessed by how City approach them.
He explained: "You like to test yourselves against the best, Manchester City are the best, and we will try and make it an uncomfortable afternoon for them.
"You have to be, more than ever, focused on yourself instead of your opponent. You have to prepare every player as much as you can and be tight in your game plan. We have the experience that in these games, you can get results and we will fight for the chance.
"We have to be at our best. We have to be brave too and trust our abilities and our skills."