“It certainly wasn’t something I had been contemplating and only arose two weeks ago,” said Griffiths at the time of the announcement.

Griffiths shocked the football club when he informed them of his decision, noting the difficulty of informing his teammates and coaches.

Neil Balme, Richmond’s head of football, said the news came as a shock: "coming in to season 2018, we expected Ben to put together a strong pre-season and again feature as a forward target for us."

“However, we understand this opportunity was too good for him to say no to and we support his decision."

Writing in Player’s Voice, Griffiths said the Tigers’ 2017 flag was his best moment in football, despite not being part of the winning side on grand final day.

“It was the greatest moment I’ve been part of in footy. I won’t forget the smile on David Astbury’s face for as long as I live,” he said.

Griffiths, who was introduced by his new coach to teammates as a professional rugby player, said Australian players in American football were still a “mystery to the locals,” saying his teammates “seemed convinced I’d been playing a cross between rugby and soccer”.

The college football season begins in August 2019.