The Welsh international trio are in action for their country against Australia this weekend and will then feature for the Babaas at Twickenham a week later on December 5.
Roberts, Halfpenny and Powell will therefore miss the Blues' Magners League home tie with Connacht at the Cardiff City Stadium the following day.
All three players impressed for Ian McGeechan's 2009 Lions on their 10-match adventure of the Republic, playing a total of 12 games between them and with Roberts being named HSBC Player of the Tour.
While the final Barbarians starting line up is yet to be named, the trio have been included in a star-studded 22-man squad for what should be a hugely entertaining encounter.
Halfpenny, Roberts and Powell are set to line up alongside a number of adversaries from the Lions' summer tour of with Springboks Bryan Habana, Jaque Fourie, Morne Steyn, Fourie du Preez, Bismarck du Plessis, Tendai 'Beast' Mtawarira, Victor Matfield, Danie Rossouw and Schalk Burger all included.
Also named in the Babaas squad are former Leinster hero Rocky Elsom and fellow Wallaby figureheads Matt Giteau, George Smith and Drew Mitchell, as well as exciting young scrum-half Will Genia.
Out-of-favour All Blacks wing Joe Rokocoko will also wear Babaas colours against his home country after falling down the pecking order back in New Zealand.
Barbarians squad (vs New Zealand, Saturday, December 5, Twickenham)
Backs: Leigh Halfpenny (Wales), Bryan Habana (South Africa), Joe Rokocoko (New Zealand), Drew Mitchell (Australia), Jamie Roberts (Wales), Jaque Fourie (South Africa), Morne Steyn (South Africa), Matt Giteau (Australia), Fourie du Preez (South Africa), Will Genia (Australia)
Forwards: Bismarck du Plessis (South Africa), Stephen Moore (Australia), Tendai Mtawarira (South Africa), WP Nel (Free State Cheetahs), Salvatore Perugini (Italy), Victor Matfield (South Africa), Danie Rossouw (South Africa), Carlo del Fava (Italy), Rocky Elsom (Australia), Schalk Burger (South Africa), George Smith (Australia), Andy Powell (Wales)