Broncos big bopper Payne Haas and Warriors skipper Tohu Harris are the only players to earn selection in each of the opening three rounds.
In two stints adding up to 46 minutes on the field, Tapine put his hand up for 15 carries and achieved hauls of eight metres or more on 12 of them, in addition to getting through 32 tackles in Canberra's 24-20 win over the Sharks.
He was well assisted by fellow middle Whitehead, who did plenty of the tough stuff with six decoys in addition to nine carries for eight metres or more.