Warriors and Kiwis great Manu Vatuvei may not play rugby league again after the discovery of a brain cyst.

Vatuvei revealed on Wednesday he learned of the serious diagnosis late last year, just after launching what he hoped would be a credible crack at professional boxing.

The 33-year-old was forced to immediately hang up his gloves and told to never fight again.

He is reluctant to give away rugby league, even though he hasn’t played for two years since cutting short a stint at Super League club Salford after rupturing his Achilles tendon.

“I haven’t really announced my retirement or anything because I’m in denial that I can still play,” Vatuvei told journalists in Auckland, where he is helping prepare the Tonga team to face New Zealand on Saturday.

The former powerhouse winger said he had felt no symptoms typical of a cyst on the brain, yet medical staff believe it had been present throughout his 14-year rugby league career.

He still went ahead with his maiden heavyweight boxing fight last December, which he won.

All of his subsequent fights were cancelled and he made the unlikely recent switch to ballroom dancing to occupy himself, going on this month to win New Zealand’s latest version of television show Dancing with the Stars.

“When I did this dancing it made it easier for me to get over it,” he said.

“I had to get over it somehow … it was a tough challenge for myself and I’ve enjoyed it.”

Vatuvei is the 10th-highest tryscorer in NRL history with 152 tries and sits fifth on the list of single-club players – topped by 190 from Melbourne great Billy Slater.

His 22 Test tries are the most by any player for the Kiwis.