Greenberg started his career as a sports journalist with the Mail on Sunday, breaking the story in 1995 that cost then Arsenal manager George Graham his job after revealing that he had accepted a "bung" from a Norwegian agent.

He went on to become the Evening Standard’s youngest sports editor before moving into public relations when he was appointed the first director of communications at Premier League club Chelsea.

Greenberg worked closely with the club’s new manager Jose Mourinho before leaving Chelsea in 2009 to join England’s ill-fated World Cup bid, which ended embarrassingly when it was eliminated in the first round with only two votes.

In 2011 he joined News International - now News UK - as the publisher's director of corporate affairs.

The period coincided with the phone-hacking crisis that led to the shutting down of Britain’s most popular Sunday tabloid, the News of the World.

Greenberg spent a further nine years at News International, initially as executive member of its Management and Standards Committee, set up following the phone-hacking scandal.

From 2013 to 2020 he worked as as global head of rights at News UK, setting up Dow Jones Sports Intelligence, dedicated to providing sports brands and their sponsors with data.

Among the events he regularly attended to help promote the product was SportAccord and the IF Forum.

Before he fell ill, Greenberg he worked as head of international, business and corporate development of sports content start-up The Athletic.

Greenberg, a life-long fan of Tottenham Hotspur, despite working for Chelsea, represented Britain in swimming at the 2009 Maccabiah Games in Tel Aviv.

He was diagnosed with Creutzfeldt-Jakob disease earlier this year.

Chelsea chairman Bruce Buck led tributes to Greenberg.

"We were deeply saddened to hear of Simon’s illness, and then devastated to learn of his passing," he said.

"Simon’s time at the club covered a period of incredible growth and new success, and he thrived under the pressure the media attention provided. 

"Simon played a vitally important role and helped carry the club through those hectic times with enthusiasm and wit, just two of his many impressive characteristics that made him such a pleasure to work with and be around."

Greenberg married Fran Jefferson, a music industry executive, in 2013.

She survives him with their son, Sam, as well as Coco and Sukie, Fran’s daughters from a previous marriage.