Mackintosh and fellow Highlanders Adam Thomson and Jimmy Cowan were included in a squad of 25 players in contention for the Bledisloe Cup test in Hong Kong and the Grand Slam tour.
The squad does not include Canterbury or Wellington players, who are preparing for the Air New Zealand Cup final.
Mackintosh has been labelled an All Black-in-waiting since he was about 15. This time, the Southland man mountain is a serious chance.
After an outstanding first full Super 14 campaign, Mackintosh maintained his form for the surprising Stags, who reached the Air New Zealand Cup semifinals.
He is a technically proficient scrummager and an excellent defender whose sheer size makes him a valuable member of the front row.
Mackintosh also has an impeccable pedigree, having captained national sides and his province. He is also odds-on to become the first Southlander to captain the Highlanders.
The All Blacks need more propping options with Carl Hayman and Greg Somerville having departed within 12 months of each other.
Thomson is again the only Otago player named, hardly surprising given the province's dreadful run this season. Lock Tom Donnelly was included in a training squad earlier this year but is out of favour.
Thomson secured his place in the squad throughout the domestic season but he may face a stiff challenge to book his ticket on the Grand Slam tour.
Newcomers Tanerau Latimer (Bay of Plenty) and Scott Waldrom (Taranaki) are included as specialist openside flanker options, while Liam Messam (Waikato) could finally get a chance in the loose forward mix.
With Jerome Kaino's place secure and Richie McCaw, Kieran Read and Rodney So'oialo to be available after the final, Thomson could be squeezed out.
Taranaki lock Jason Eaton gets another chance to press for a recall, while Tasman prop Ben Franks will challenge Mackintosh for a front-row berth.
The training squad goes into camp today and plays a training game against a NZ Barbarians side at Trusts Stadium, Waitakere, on Wednesday. The All Black squad to tour Hong Kong, the United Kingdom and Ireland will be named on Sunday.
• All Blacks - Wider training squad
John Afoa, Anthony Boric, Jimmy Cowan, Stephen Donald, Jason Eaton, Ben Franks, Andrew Hore, Richard Kahui, Jerome Kaino, Tanerau Latimer, Sione Lauaki, Jamie Mackintosh, Keven Mealamu, Liam Messam, Mils Muliaina, Josevata Rokocoko, Sitiveni Sivivatu, Adam Thomson, Brad Thorn, Isaia Toeava, Anthony Tuitavake, Scott Waldrom, Ali Williams, Tony Woodcock, Rudi Wulf.
