Borussia Dortmund defender Mats Hummels has admitted that he is "desperate" to get one over on former manager Jurgen Klopp in next month's Europa League tie.
Liverpool boss Klopp will return to the Westfalenstadion on April 7 for the quarter-final fixture, before the two sides face off in the return leg seven days later at Anfield.
It is expected to be an emotional reunion for the German, who spent seven years at the club before leaving last summer, but Hummels insists that friendship will be pushed to one side.
"The tie with Liverpool is one where we are simply desperate to beat Klopp. We have to beat him," he told German broadcaster 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."
Klopp guided Dortmund to two Bundesliga titles, the German Cup and also took them to the Champions League final in 2013.