But he was given even more reason to debate the merits of his pugilistic pursuit with Australian Rugby Union boss Bill Pulver after his knockout win over Newcastle's Warren Tresidder in Brisbane on Wednesday night.
No doubt Wallabies coach Ewen McKenzie was on board after enjoying a ringside view as Cooper ensured a perfect 2-0 professional record by flooring the former cage fighter early in the fourth and final round.
Their fight was on the undercard of Anthony Mundine's WBA light middleweight fight with New Zealand's Gunnar Jackson.
Pulver may still need some convincing after hinting boxing could be off the table when they negotiate a new deal after Cooper's contract expires later this year.
However, the Queensland Reds playmaker hopes nothing will interfere with his budding boxing career, crediting it with transforming him into someone now considered Wallabies captaincy material.
Not a bad effort from someone who appeared in the Wallabies wilderness after describing the national team environment as "toxic".
And few on Wednesday night could argue with Cooper's boxing ability after witnessing his impressive victory.
Tresidder - in just his second professional bout but backed by 25 years of cage fighting - started the aggressor before Cooper worked away with his left jab.
Cooper, 25, capped a complete performance when he made short work of Tresidder - aged 40 - soon after emerging from his corner in the final round.
Still, Cooper looked to try to help the veteran up after he downed the Newcastle fighter.
"I just wanted to show boxing isn't all about trash talking," Cooper said of his actions.
"Boxing can also be about having a beer with your opponent after the fight."
Cooper raised eyebrows when he missed the Reds' final Super Rugby trial against the Chiefs to fight Barry Dunnett last February, emerging with an impressive first round knockout win on professional debut.
But this time Cooper went to great lengths not to let his upcoming bout interfere with the Reds' pre-season campaign in a bid to show Pulver that he could successfully juggle the two sports.
Reds teammate Will Genia - who was a keen ringside observer along with most of the Queensland squad on Wednesday night - backed Cooper's call.
"It's a tricky one in that Bill (Pulver) is the boss and what he says goes but if he asked my opinion he is in the best shape that he has ever been, mentally he is in a really good space," he said.
"Boxing gives him (Cooper) confidence which flows into his rugby, which can only be a good thing."