TOKYO—The Olympics must not be a burden on medical systems, Japan’s chief government spokesman said on Friday, amid worries that daily athlete testing will tax health resources already stressed in fighting a rebound of COVID-19 cases. The Games will be held in a manner that makes everyone feel safe, Chief Cabinet Secretary Katsunobu Kato told reporters, responding to concerns raised by a nurses’ union that the world’s biggest sporting event will sap medical resources needed by the public. Tokyo 2020 organisers this week issued the second edition of “playbooks” that lay out infection prevention standards for the Summer Games, which are due to start in less than three months after a one-year delay because of the pandemic. The rules require daily testing of athletes and restrict their use of public transportation, complicating logistics in more remote locations. The venue for surfing in the Tokyo Olympics refused to set up COVID-19 …