Tietjens' season ended in unlucky fashion when he ruptured his Achilles tendon playing a game of touch last week.
The 27-year-old loose forward, from Manawatu, was in his second season with the Highlanders.
''There was no reason for the injury. He had no tightness before the game,'' Highlanders coach Jamie Joseph told the Otago Daily Times yesterday.
''It was just an unfortunate accident.''
Tietjens is the second Highlander to be scratched for the season. Outside back Declan O'Donnell (shoulder) is gone, and it has been confirmed he will be replaced by Waikato utility Trent Renata.
All Black midfielder Tamati Ellison is recovering from shoulder surgery but it is hoped he will be back before the end of the Super 15.
No 8 Nasi Manu has a hamstring problem and utility forward Jake Paringatai has a broken hand.
Tietjens' misfortune is good news for Otago captain Paul Grant, who has been brought into the Highlanders as temporary cover for the loose forwards.
''We have interim cover with Paul and we will be looking for permanent cover at some stage,'' Joseph said.
A wildcard for the replacement spot could be Adam Thomson, the All Black loose forward, who has no rugby commitments until his expected move to Japan next season.
Joseph, well accustomed to dealing with injuries, has not yet pressed the panic button.
''We don't play until the end of February. If this was the end of February, I'd be more worried.
''I'm used to having injuries. It is all part of it. That is why we have big squads.
''Our situation has been compounded because guys like John Hardie, Colin Slade and Lima Sopoaga are returning from surgery. They will return in time but haven't participated fully in pre-season training.''
The Highlanders will tramp 25km into the Greenstone Valley on Saturday morning to a base camp for three days to give the squad ''an appreciation of the type of people and terrain they represent in the deep South,'' Joseph said.
The players will be given an understanding of what is expected from management and the behaviour they want from the team on and off the field.
Former All Black Brad Thorn will fly from Japan and meet the team in Queenstown today.
''He will come from Japan in the middle of winter to go up the Greenstone, where temperatures could reach 30degC,'' Joseph said.
The team's returning All Blacks, plus new recruits Ma'a Nonu and Tony Woodcock, will also join the team for the Queenstown experience.
''It will give Ma'a Nonu and the new players who are not from the South an understanding of the type of area we are representing,'' Joseph said.
