The Leipzig team is out of form. In the Bundesliga, they lost to Union Berlin and Gladbach. In the Europa League match, they lost 3-1 against the Rangers. It is very difficult for them to qualify for the Champions League. The next two matches will be against Arminia and Augsburg. They have to win these two matches if they want to qualify for the Champions League.
Bielefeld and Augsburg are not very strong opponents. Leipzig had some difficulties in the last weeks, but I think they'll win both games. Freiburg also still has a very difficult game in Leverkusen, both direct competition for Leipzig. They will take away each other's points. I doubt Freiburg will be able to gain 6 points.
But you are right, Leipzig will (very likely) need 2 wins to conquer rank 4, otherwise they are probably stuck on rank 5.