Ed Harris may have an extensive list of credits to his name but the esteemed actor has revealed the one role he turned down which he probably shouldn't have.

The American star, who currently appears as William - otherwise known as the Man in Black - in HBO series Westworld, recounted how Stanley Kubrick once offered him a role in his 1987 Vietnam War film Full Metal Jacket only to turn the filmmaker down.

If he'd have accepted, Harris would have played Gunnery Sergeant Hartman, the drill instructor memorably played by former Marine R. Lee Ermey who passed away last month.

“Stanley Kubrick called me up one day and asked me to play the sergeant in Full Metal Jacket, and I said no,” Harris told The Los Angeles Times, adding: [Ermey] was great and did a much better job than I would have done. But that always makes me kind of go, 'What were you thinking about?'.

“It might have been that I had a few too many beers that night. It was foolish.”

Harris, who also stars in Netflix film Kodachrome, reflected upon his credits which include films Glengarry Glen Ross, Apollo 13, The Rock and The Truman Show.

“The thing was when I first started out as a younger guy, I was already losing my hair - and you weren't a lead in a film if you didn't have hair, period. So I would just try to get the most interesting part I could play in whatever it was.”

Harris remained tight-lipped on what Westworld season 2 has in store for his character, stating simply he will “get paid back a lot” in episodes to come. Whether he'll have a part to play in the newly-confirmed third season remains to be seen.