The defending German champions will head into the clash at the Signal-Iduna Park second in the league table, 20 points behind leaders Bayern Munich.
"We are in the middle of an exciting season," he told reporters. "We may not have done everything right, but we have done enough to lead the rest of the league.
"We are in second place, and it may sound a bit strange but we are not over the moon as some of the games should have really gone our way.
"Freiburg are having an unbelievably good season. Anything less than 100% will not be enough."
Freiburg are currently eighth in the Bundesliga.