Germany’s long-serving team doctor Hans-Wilhelm Mueller-Wohlfahrt quit on Friday after 23 years in the job, becoming the first casualty of the country’s World Cup flop.

“I have decided to retire as team doctor. I have informed the Germany team manager Oliver Bierhoff and coach Joachim Loew,” the 75-year-old told DPA news agency.

Known fondly as ‘Mull’, the doctor is the first member of Loew’s backroom staff to quit following the 2014 World Cup winners’ shock first round exit at this year’s tournament in Russia.

“I had 23 fantastic years with extraordinary achievements and great results. During those years, wonderful friendships were made and the atmosphere was was one of great trust,” said Mueller-Wohlfahrt, who will remain the doctor of Bayern Munich, where he has worked for more than 40 years.

“I will remain in close contact with the national team and wish everyone a lot of success for the future,” he added, saying he was always available to help the national team again.

Mueller-Wohlfahrt began working with the national team in 1996 when Germany won a third European title.

During his career, Mueller-Wohlfahrt also worked in other areas, even advising athletics superstar Usain Bolt.