Uncapped 21-year-old loose forward Peter Lakai and lock Josh Lord, who featured in the Rugby Championship, have been called up as cover and will travel with the squad on Thursday, the All Blacks said.
"We are excited to be welcoming Josh back into the group and giving Peter Lakai his chance to wear the All Blacks jersey," All Blacks coach Scott Robertson said in a statement.
"We will assess the status of Ethan, Luke and Dalton's injuries prior to travelling to England, to determine whether we are going to require that additional injury cover."
Blackadder has been sidelined by a calf injury, Jacobson has a fractured thumb and Papali'i is struggling with an upper hamstring issue.
Seven members of the All Blacks XV squad, who will play Munster and Georgia on their November tour, will also be travelling to Japan as training cover.
These players will then join the All Blacks XV squad in Ireland, with the possible exception of one further call-up to cover the 36th spot in the All Blacks squad, the team said.
The All Blacks start their tour against Japan in Yokohama on October 26, before meeting England at Twickenham on November 2.
They then face Ireland, France and Italy in successive weeks in November.
ALL BLACKS SQUAD:
Forwards: Asafo Aumua, Codie Taylor, George Bell, Ethan De Groot, Tyrel Lomax, Fletcher Newell, Pasilio Tosi, Ofa Tu'ungafasi, Tamaiti Williams, Scott Barrett, Tupou Vaa'i, Patrick Tuipulotu, Sam Darry, Josh Lord, Sam Cane, Samipeni Finau, Peter Lakai, Ardie Savea, Wallace Sititi
Backs: Cam Roigard, TJ Perenara, Cortez Ratima, Beauden Barrett, Damian McKenzie, Jordie Barrett, David Havili, Rieko Ioane, Anton Lienert-Brown, Billy Proctor, Caleb Clarke, Will Jordan, Ruben Love, Stephen Perofeta, Sevu Reece, Mark Tele'aÂ
