It is said that “For many reasons, Agile seems to work best when a [line manager] does not assume either the Product Owner or Scrum Master role.” But if so, then who should be that line manager? The above quote comes from SAFe, and although the latest version of the official Scrum Guide has nothing to say about the topic, it is an often-repeated truth when talking about Scrum. But that obvious follow-up question is not discussed nearly as often.