bayern munich 's long-serving doctor hans-wilhelm muller-wohlfahrt quits .
german champions lost 3-1 in the champions league to porto this week .
muller-wohlfahrt claimed he and his staff were blamed for the defeat .
bayern release statement on friday thanking muller-wohlfahrt for his services and saying they ` regret ' his decision .
guardiola on friday said he ` respects ' muller-wohlfahrt 's decision .
pep guardiola seemed to place blame on injuries in post-match interview .