Retallick blow for battered Chiefs
The powerful second row forward fractured his ribs in his team's 32-36 loss to the high-flying Lions in Hamilton at the weekend.
The Chiefs medical staff said Retallick could be sidelined for up to six weeks.
A Chiefs statement said Retallick wasn't considered for their two-match tour to South Africa and Argentina and is expectd to return to play in Round Seven or Eight.
Wing Shaun Stevenson is also unavailable, with a shoulder complaint suffered in the opening round win over the Crusaders.
All Black hooker Hika Elliot is still sidelined by concussion symptoms.
The Chiefs have otherwise named a squad close to full strength for games against the Southern Kings in Port Elizabeth and the Jaguares in Buenos Aires.
Wold Cup-winning All Black flyhalf Stephen Donald is yet to play this season, but is included in the 27-man tour squad.
Chiefs squad:
Backs: Damian McKenzie, James Lowe, Latu Vaeno, Glen Fisiiahi, Sam McNicol, Seta Tamanivalu, Anton Lienert-Brown, Charlie Ngatai, Aaron Cruden (co-captain), Stephen Donald, Tawera Kerr-Barlow, Brad Weber.
Forwards: Michael Leitch, Maama Vaipulu, Sam Cane (co-captain), Tom Sanders, Johan Bardoul, Taleni Seu, James Tucker, Michael Allardice, Hiroshi Yamashita, Siate Tokolahi, Atu Moli, Pauliasi Manu, Mitchell Graham, Rhys Marshall, Nathan Harris.
