In an interview with The Ice Project podcast, Cooper revealed he was ready test the waters of 13-man rugby league when in discussion with show host and former Warrior Isaac John.
Currently plying his trade with Kinetsu Tigers in Japan, the 31-year-old said league has always been an attraction to him since playing with Tokoroa early in his career.
Cooper also revealed both he and Williams have previously discussed teaming up, with the Toronto Wolfpack a potential destination.
“I want to play with Sonny before we both retire. But I wouldn’t mind playing NRL either, just for one season or even just come and do some training with the lads to see what it is like,” he said.
“If it doesn’t happen, it doesn’t happen. I am happy with what I have been able to achieve, but if the opportunity arose I would love to do it.”
Cooper and league seem to be becoming a suitable match-up, allowing more time to shape up and being more reliant on one-on-one encounters.
“A lot of people say I would come and kill it, and I know I can play it,” he said.
“For me it seems easy in terms of the theory… athletically though, it is a lot harder.
“I look at the game and every time I watch it, I know how much I would love to play and test myself at a professional level. I still want to play, it’s just figuring out whether it is possible.”
Cooper also revealed how close he was to signing with an NRL outfit at the start of the decade.
“I basically signed with Parramatta, and then I dropped my nuts and pulled out,” he said.
“I was scared and felt like I would miss out on achieving what I wanted to achieve in rugby. I didn’t want to be a guy that floated in between and did nothing.
“I am sort of glad I didn’t go to Parra because a year later we won the comp with the Reds, and Parra didn’t do too well after that.”