"They're no longer with us. They're back in New Zealand, so we just hope they're handling that as well as they can."
He said the 30-man squad had been selected "generally on form".
"It was an incredibly difficult process; all the players who missed selection are not only outstanding players but special people. We are close as a group which made this selection all the more difficult."
Henry said Gear, Sivivatu, Smith, Messam, Crockett and Hoeata would be included in a pool of players to cover for any injuries during the tournament.
"Generally, this team has been selected on current form. We believe there is a good balance; a blend of experienced All Blacks - with nine players who have played more than 50 Tests - while at the other end of the scale we have seven players who have played fewer than a dozen tests who bring youthful enthusiasm to the side."
He said Gear had not shown the form displayed by Guildford in recent weeks.
Henry said Guildford was selected over other wing prospects Sivivatu and Gear because of his superior work rate and desire.
He had improved dramatically since his All Black debut in 2009, Henry said.
"He's probably just played with a little bit more energy than the others, a bit more desire... Because of that energy, because of that availability, he got the nod."
Throwing the cat among the pigeons, Henry touted South Africa test star Israel Dagg as a potential starting fullback at the Rugby World Cup.
North Harbour lock Anthony Boric was also given the nod ahead of new All Black Hoeata, despite not playing since injuring his foot for the Blues during the Super 15 finals series.
Boric returns to rugby this week in Harbour's provincial rugby match against Wellington.
The All Blacks squad are in Brisbane preparing for the final match of the Tri Nations against Australia at Suncorp Stadium this Saturday.
Forwards:
Hookers
Corey Flynn, Canterbury (14 tests)
Andrew Hore, Taranaki (54)
Keven Mealamu, Auckland (85)
Props
John Afoa, Auckland (33)
Ben Franks, Tasman (11)
Owen Franks, Canterbury (23)
Tony Woodcock, North Harbour (75)
Locks
Anthony Boric, North Harbour (20)
Brad Thorn, Canterbury (51)
Samuel Whitelock, Canterbury (17)
Ali Williams, Auckland (65)
Loose forwards
Jerome Kaino, Auckland (41)
Richie McCaw, (capt) Canterbury (97)
Kieran Read, Canterbury (31)
Adam Thomson, Otago (21)
Victor Vito, Wellington (7)
Backs:
Halfbacks
Jimmy Cowan, Southland (47)
Andy Ellis, Canterbury (20)
Piri Weepu, Wellington (48)
First five-eighths
Daniel Carter, Canterbury (82)
Colin Slade, Canterbury (5)
Midfielders
Richard Kahui, Waikato (12)
Ma'a Nonu, Wellington (58)
Conrad Smith, Wellington (48)
Sonny Bill Williams, Canterbury (7)
Outside backs
Israel Dagg, Hawke's Bay (7)
Zac Guildford, Hawke's Bay (6)
Cory Jane, Wellington (24)
Mils Muliaina, Waikato (97)
Isaia Toeava, Auckland (31)