Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: Bundesliga champions Bayern Munich have swooped to hire rivals Borussia Dortmund's club doctor. The Bavarian club announced that Andreas Schlumberger will form part of Pep Gaurdiola's backroom operation ahead of the new season, replacing Hans-Wilhelm Muller-Wohlfahrt who quit in April. Muller-Wohlfahrt, who had served Bayern for 40 years, walked away from the club after the medical department were blamed for the Champions League defeat by Porto towards the end of last season. Bayern were beaten 3-1 by the Portuguese outfit in the quarter-final first leg and Guardiola was forced to field an under-strength side after several players were left struggling with injury.Bayern confirmed appointment of Borussia Dortmund doctor on ThursdayAndreas Schlumberger replaces Hans-Wilhelm Muller-WohlfahrtLong-serving Bayern doctor quit in April after being blamed for defeat 
 Question:Schlumberger is the latest person to swap _ for Bayern after Robert Lewandowski and Mario Gotze made controversial moves in 2014 and 2013 respectively.

Borussia Dortmund