Stratton also played for the provincial Barbarians in this year's 13-7 loss to the British and Irish Lions in Whangarei.
Ere Enari, meanwhile, has been ruled out for the season with a broken leg.
Of the Crusaders' 38-man squad, a dozen are on the All Blacks' end-of-year tour - including Kieran Read, Sam Whitelock and Ryan Crotty.
That number does not include a host of injured All Blacks including starting props Owen Franks and Joe Moody, as well as Israel Dagg.
Veteran midfielder Tim Bateman is also with the Maori All Blacks.
"I'm really proud of the squad we've announced and, as a coaching group, we're looking forward to seeing what we can achieve with this team," Robertson said.
"Each of the players we have named brings something different to the mix, but I believe the combination of skills we have here is strong and the character of each of these men will add value to the Crusaders in 2018."
2018 BNZ Crusaders Squad Announcement #crusadeon
Posted by Crusaders on Tuesday, 31 October 2017
Crusaders
Forwards
Michael Alaalatoa, Scott Barrett, Ethan Blackadder, Wyatt Crockett, Mitchell Dunshea, Owen Franks, Ben Funnell, Billy Harmon, Oliver Jager, Andrew Makalio, Joe Moody, Tim Perry, Kieran Read, Luke Romano, Pete Samu, Tom Sanders, Quinten Strange, Jordan Taufua, Codie Taylor, Matt Todd, Sam Whitelock.
Backs
Tim Bateman, George Bridge, Ryan Crotty, Israel Dagg, Mike Delany, Mitchell Drummond, Braydon Ennor, Jack Goodhue, Bryn Hall, David Havili, Mitchell Hunt, Will Jordan, Jone Macilai, Manasa Mataele, Richie Mo'unga, Jack Stratton, Seta Tamanivalu.
CHIEFS SQUAD - McKenzie joins brother in squad
The Chiefs will take on a markedly different complexion in 2018 after losing a score of regulars to European rugby.
New coach Colin Cooper has introduced seven reinforcements to the side that fell at the semi-final stage of this year's Super Rugby campaign, including Te Toiroa Tahuriorangi, Luke Jacobson and the returning Marty McKenzie.
The 20-year-old Jacobson, a loose forward by trade, was the captain of New Zealand's under-20 World Championship-winning side this year.
New first-five Tiaan Falcon was also part of that side and is likely to provide cover for Damian McKenzie, who will switch from fullback to No.10.
The Chiefs have lost plenty of stalwarts over the off-season, including playmaker Aaron Cruden, halfback Tawera Kerr-Barlow and James Lowe.
Coach Dave Rennie also took up a job with the Glasgow Warriors.
They have nevertheless retained seven current All Blacks, including club captain Sam Cane, Brodie Retallick, McKenzie and Anton Lienert-Brown.
"There's a high level of experienced players returning in 2018, which combined with the addition of new ambitious and enthusiastic young players completes a great group of men which we're really looking forward to guiding," Cooper said.
Former Crusaders assistant and Bath boss Tabai Matson, formerly Cooper's assistant with the Maori All Blacks, is also joining the Chiefs.
The rest of Cooper's staff comprises returning coaches Neil Barnes, Andrew Strawbridge and Carl Hoeft.
Cooper said he was pleased with the balance of his group.
Chiefs
Props: Aidan Ross, Atunaisa Moli, Kane Hames, Mitchell Graham, Nepo Laulala, Sosefo Kautai.
Hookers: Liam Polwart, Nathan Harris, Samisoni Taukei'aho
Locks: Brodie Retallick, Dominic Bird, Fin Hoeata, Michael Allardice
Loose forwards: Lachlan Boshier, Liam Messam, Luke Jacobson, Mitchell Brown, Mitchell Karpik, Sam Cane, Taleni Seu, Tyler Ardron.
Halfbacks: Brad Weber, Jonathan Taumateine, Te Toiroa Tahuriorangi
First five-eighths: Damian McKenzie, Marty McKenzie, Tiaan Falcon
Midfield: Alex Nankivell, Anton Lienert-Brown, Charlie Ngatai, Johnny Faauli, Regan Verney.
Midfield/outside back: Tim Nanai-Williams
Outside backs: Levi Aumua, Sam McNicol, Shaun Stevenson, Solomon Alaimalo, Toni Pulu.
HIGHLANDERS - Lomax joins seven new faces
The Highlanders have added eight players to their Super Rugby squad for 2018, including prodigious prop Tyrel Lomax.
The 21-year-old front-rower, son of former Kiwis star John, has moved across from the Melbourne Rebels in the hope of cracking the All Blacks.
He played for Tasman in this year's provincial competition.
He joins four new backs and three other new forwards in coach Aaron Mauger's squad, as they hope to reclaim the trophy they won in 2015.
"It's been interesting watching the Mitre 10 Cup, as you do get to see a lot of younger players getting an opportunity to display their abilities. We're very happy with the group of younger guys we have managed to pick up," Mauger said.
Mauger's youthful troupe will be complemented by a number of senior All Blacks, including Ben Smith, Aaron Smith and Liam Squire.
It also includes eight current or former All Blacks, as well as seven Maori All Blacks - including captain Ash Dixon.
"We have assembled a well-balanced and exciting squad that will create real competition for starting spots," Mauger said.
"We have selected players that fit the playing profile to execute our game and stretch our capabilities as a team."
The squad will reconvene for training in late November.
Highlanders
Forwards: Luke Whitelock, Liam Squire, Elliot Dixon, Shannon Frizell, Dillon Hunt, James Lentjes , Dan Pryor, Alex Ainley, Tom Franklin, Jackson Hemopo, Josh Dickson, Pari Pari Parkinson, Kalolo Tuiloma, Siate Tokolahi, Daniel Lienert-Brown, Tyrel Lomax, Aki Seiuli, Guy Millar, Ash Dixon, Greg Pleasants-Tate, Liam Coltman
Backs: Ben Smith, Josh McKay, Tevita Li, Waisake Naholo, Tevita Nabura, Thomas Umaga-Jensen, Richard Buckman, Patelesio Tomkinson, Matt Faddes, Rob Thompson, Teihorangi Walden, Lima Sopoaga, Fletcher Smith, Josh Ioane, Josh Renton, Kayne Hammington, Aaron Smith
BLUES SQUAD - Kirkpatrick returns to Blues
First five Daniel Kirkpatrick has returned to the Blues for the 2018 season after a six-year stint in France.
Kirkpatrick joins Bryn Gatland and Stephen Perofeta in the battle for the number 10 with Hurricanes signing Otere Black ruled out for the entire season after suffering an ACL injury.
Kirkpatrick, who played six games for the Blues in 2010, has been playing for French second division side SC Albi after three seasons at Castres.
Other additions to the Blues 2018 squad include North Harbour's Mike Tamoaieta, Tasman's Isaac Salmon and Southland's Matt Johnson while Caleb Clarke, Dalton Papalii and Tamati Tua join the team after coming through the Blues development programme.
In another injury blow for the Blues, loose forward Blake Gibson will be out for the first part of the Super season in recovery from an operation on his shoulder.
"We have a settled core of All Blacks and experienced Super Rugby players as our nucleus," coach Tana Umaga said.
"We've seen a number of our 2017 team produce excellent form in the Mitre 10 Cup, and others who have played well to earn their opportunity.
"We have to work harder than we have before, but above all else have players wanting to progress both on and off the field."
Blues squad:
Hookers: Leni Apisai, Matt Moulds, James Parsons.
Front row: Alex Hodgman, Sione Mafileo, Pauliasi Manu, Isaac Salmon, Mike Tamoaieta, Ofa Tuungafasi.
Locks: Gerard Cowley-Tuioti, Josh Goodhue, Scott Scrafton, Patrick Tuipulotu, Jimmy Tupou
Loose forwards: Blake Gibson, Akira Ioane, Jerome Kaino, Dalton Papalii, Glenn Preston, Kara Pryor, Murphy Taramai.
Halfbacks: Sam Nock, Augustine Puli, Jonathan Ruru.
First Five: Otere Black/Daniel Kirkpatrick, Bryn Gatland, Stephen Perofeta.
Midfield: Matt Johnson, George Moala, Tamati Tua, TJ Faiane, Sonny Bill Williams.
Outside backs: Caleb Clarke, Michael Collins, Matt Duffie, Rieko Ioane, Melanie Nanai, Jordan Trainor.
HURRICANES - 11 new faces in squad
There are 11 new faces in the Hurricanes squad with All Blacks rookie Asafo Aumua joining a strong trio of hookers at the franchise. Aumua will battle with All Blacks starting number two Dane Coles and Ricky Riccitelli for a spot in the match-day squad.
Other new faces include forwards Alex Fidow, Toby Smith, Murray Douglas, Gareth Evans, Sam Henwood with Jamie Booth, Finlay Christie, Jackson Garden-Bachop and Ihaia West in the backline.
Hurricanes squad:
