Brisbane legend Gorden Tallis tells winger Corey Oates to toughen up ahead of backrow shift

Brisbane legend Gorden Tallis has told Corey Oates to toughen up ahead of his move to the back row.

Oates will turn out in the back row in the Broncos' final NRL trial against Queensland Cup side the Papua New Guinea Hunters.

Ahead of a permanent shift to the forwards, the former Queensland winger has been offered no guarantees by coach Wayne Bennett.

Bennett took a swipe at Oates when he said he needed to "toughen up" to play back row and he risked being shunted to reserve grade if the move didn't work out.

Oates will start the year off the bench, due to the calibre of their all-international back row.

He has endured a sometimes rocky relationship with Bennett, with the master coach often taking swipes at his attitude during media conferences.

Tallis, who won two NRL premierships and one Super League title under Bennett, said Oates had the makings of a powerful second-rower but his success depended on his commitment and attitude.

"He played back row as a kid," Tallis said at the Fox League launch.

"He does that many hit-ups anyway and he can tackle as well.

"It's just the fitness; it's the mental toughness for him. It's got nothing to do with his ability - it's how hard he's prepared to work."

Bennett has taken a big gamble with Oates' move to the back row, weakening his outside-back stocks.

Brisbane Broncos' Corey Oates in action at training. (AAP)

However, Tallis said it added much-needed size to the Broncos' pack, something for which they have been criticised as lacking over the past few seasons.

"The big investment is Corey Oates coming off the wing, it might talk a while," Tallis said.

"If he can make that transition work, he can get into the back row and make it his own."