Some readers will be imagining a baby elephant in the room with Ben Mendelsohn. So, let's just get this out of the way first. Like everybody else associated with the Star Wars project, the Australian actor is allowed to say nothing much about his role in the saga. We know that he appears in Star Wars: Rogue One, a prequel involving a scheme to steal the plans of the Death Star, but we will know little else for a year.

“Ah outside of what you know it would be very shoddy of me to say more,” he groans. “Particularly for the fans – the kids – it just wouldn’t be fair.”

Star Wars aside, Ben Mendelsohn is not backwards in speaking out. Maybe he's making up for lost time. Now 46, he had been a busy if largely unheralded actor for 20 years, when he finally attracted attention as a hoodlum in David Michôd's rough, atmospheric Animal Kingdom (2010). Within what seemed like minutes he was transformed into the Warren Oates of his era: brilliant in The Dark Knight Rises, Killing Them Softly, The Place Beyond the Pines, Slow West and, now, opposite Ryan Reynolds as a hopelessly addicted gambler in Mississippi Grind.

"It was all Animal Kingdom," he says. "Animal Kingdom was essentially a night-and-day thing for me. When it came to outside Australia it was a whole different situation. There was maybe a one-two punch that was landed after that: The Place Beyond the Pines and Killing Them Softly. After that things were different."

Raised in Melbourne to a middle-class family, Mendelsohn stumbled into acting at school and, like so many of his compatriots, got his first break in TV soap operas. He was in 19 episodes of Neighbours. He turned up in A Country Practice and The Flying Doctors. A few minutes of online clicking will drag up a video of a teenage Ben opposite Kylie Minogue in The Henderson Kids.

“I can think of almost no Australian actors who came through who weren’t in those shows. Maybe Nicole [Kidman] wasn’t. But Mel [Gibson] was and all the rest,” he ponders.

“I’m sure in Ireland there is the same work ethic. Get on with it and don’t waste the money. They are very valuable work processes. TV is the best training. Maybe you learn some bad habits, but you learn to always come up with something.”

Mendelsohn has no problem explaining the surge of Australian talent that has swept across Hollywood in the past 20 years. It’s down to that training in TV and the revitalisation of the Australian film industry in the late 1970s.

"Australia made the first ever feature film. Not a lot of people know that," he says (The Story of the Kelly Gang from 1906). "Then it got swamped by Hollywood. When the Labour government came in the mid 1970s, Gough Whitlam started the industry up again and that was a rebirth. A generation grew up in that industry and became available for work."

Mendelsohn, now married to the admired English novelist Emma Forrest, admits that there were times in his thirties when he considered throwing it all in. “You can get by in Australia. But it’s hard if you want to do grown-up things like have a house or have children,” he says. He set himself a deadline to quit. That passed. He didn’t quit. Now, in early middle-age, he finds himself an essential character actor. The asymmetric, expressive face is perfect for finks, losers and oppressed strivers.

As we speak he is preparing to hit the Florida Keys to resume his role as the most dangerous character in Netflix's family saga Bloodline.

"It is incredibly sweet that this has happened," he says. "You don't expect it, especially when you start so young. Your expectations become so different. Things had picked up before Animal Kingdom, but nothing like this. Nothing like this."

Indeed, for many cinema fans, Mendelsohn, rather than the glossier Ryan Reynolds, will be the main draw to Anna Boden and Ryan Fleck's gritty, hard-edged Mississippi Grind. Ben plays an unstoppable, consistently unsuccessful gambler who embarks on a trip down the titular river with Reynolds's smoother hustler.

“I suspect I have met a few people over the years who are destructive gamblers,” he says. “They were in bad situations. But I don’t know quite how many I have met in my time. Partially because those guys don’t stick their hands up and say: ‘It’s me. I am a fucking degenerate problem gambler’. Ha ha.”

Like so many of us, Mendelsohn played a bit of Texas Hold ’em when, a decade or so ago, it became such a ubiquitous craze, but he never became hooked and he never became that good.

“Nah. My main skill was fucking determination. Is that even a skill?”

Probably the most important skill a hopeful actor can acquire.

Mississippi Grind is out now