Canberra behemoth Junior Paulo is looming as the most likely opponent for Paul Gallen as some of the biggest names in rugby league prepare to take their rivalries into the boxing ring.

The identity of Gallen's foe for the upcoming footy charity fight night has been a heavily guarded secret. But it's understood the forward enforcers will be the headline act in a series of bouts between NRL stars in Sydney on December 8.

Junior Paulo has impressed ringside observers of his boxing training. Credit:Jay Cronan

Paulo and Gallen almost crossed paths a month ago when the Raiders met the Sharks in the opening week of the final series. The Cronulla captain had to sit out that encounter due to injury, instead watching on as his side won the match en route to their maiden premiership victory.

Paulo, considered one of the most intimidating forwards in the game, will have a chance to earn payback for the Green Machine when he laces up for his boxing debut. There is already bad blood between supporters of the teams after Canberra coach Ricky Stuart took exception to veteran hooker Michael Ennis' mocking of the popular "Viking clap".