Just five days after leading Madrid to an unprecedented third Champions League title in succession with a 3-1 win over Liverpool, Zidane told a swiftly organised news conference he was standing down.
Speculation quickly turned to who will succeed him at the Santiago Bernabeu, with World Cup-winning Germany coach Low among those touted as potential replacements.
Germany team manager Bierhoff was consequently relieved Low put pen to paper on a new contract until 2022 just two weeks ago.
"Well, it is a little bit surprising, but when you watched him at the Champions League final, he was really relaxed and you had the feeling that he really wanted to enjoy everything," Bierhoff said of Zidane.
"When I saw his body language I was like, 'Is he thinking about something? Is he leaving the club?' It is incredibly hard for a club.
"I don't know what alternatives they have. I'm glad we just extended the contract of Jogi Low - that was very good. There are not so many managers who could be next in line for such a big club and, of course, he leaves behind a great legacy.
"But apart from that, Real will always have a chance to win the Champions League. They have a great squad and maybe this change is the next step for them. I am really curious to know who will be their next manager."