In 2011, he joined News International - now News UK - as its director of corporate affairs and made a number of media appearances at the height of the phone-hacking scandal.
He most recently worked at the Athletic as its head of international, business and corporate development.
Separately, Mr Greenberg, who was a Spurs fan, represented Team GB in swimming at the 2009 Maccabiah Games in Tel Aviv.
Heartfelt messages came pouring in for the late sports executive, with former colleagues and his alma mater, City University, leading social media tributes.
The university’s journalism department, where he enrolled in 1990, said on Thursday that it was “very sad to hear” of his passing and noted that he had “went on to become a respected sports journalist and later Fleet St’s youngest sports editor” before his career at Chelsea.
