Borussia Dortmund defender Mats Hummels wants to drive former coach Jurgen Klopp mad when he brings Liverpool to Signal Iduna Park in the Europa League.
Klopp enjoyed a hugely successful spell with Dortmund between 2008 and 2015, winning two league titles and taking them to the 2013 Champions League final.
He replaced Brendan Rodgers as the man in charge at Liverpool back in October, but will return to BVB in April when his new club and his old side lock horns in Europe.
Hummels expects an emotional encounter, but is nonetheless determined to beat Klopp and reach the semi-finals of the competition.
"The tie with Liverpool is one where we are simply desperate to beat Klopp. We have to beat him," Hummels told ZDF.
"Of course, he will get a warm welcome and a warm farewell. But I hope to drive him mad in between.
"There will be a lot of media attention. And it will be something special for the players to meet Klopp again. It will be very interesting, also on an emotional level.
"But I try not to think about it too much yet. I already said after we were paired with Liverpool that we will start thinking about it when the game is actually around the corner."
The first leg at the Signal Iduna Park takes place on April 7, with the return at Anfield scheduled for April 14.