Joubert was examined by his doctor yesterday and advised to take another week off. He informed the Otago Daily Times of his decision after training at Logan Park yesterday. He broke his thumb at an Otago training session.
"I could have played if it had been an important game," Joubert said.
"But it was not worth risking because if I bumped it I'd be out for another three or four weeks."
Southern club dynamo TJ Ioane has replaced Joubert as openside flanker and Adam Hill comes into the reserves. All Black lock Tom Donnelly takes over the captaincy from Joubert.
Goalkicking was the Achilles heel of the Highlanders but it is expected to be a strength for Otago in the ITM Cup campaign.
Former All Black Tony Brown will start as the goalkicker in the warm-up game against Tasman.
Brown is the preferred option at first five-eighth for the national championship, "but because of the compressed nature of the competition it is a role that will be shared with other players", co-coach Phil Mooney said.
The other contenders are Hayden Parker, Glenn Dickson, who filled the role against North Otago, and Tony Fenner, who is not in the squad for the Tasman game.
Dickson will be at fullback tomorrow. He kicked nine conversions from the 12 tries scored by Otago in the 78-9 win against North Otago last weekend.
"One of Glenn's great assets is to be able to play 10, 12 and fullback," Mooney said. "With Ben Smith not available it gives us the opportunity to play Glenn in that position. He has a huge punt and an underrated attacking game as well."
Tasman is a much harder proposition than North Otago.
"It is an opportunity to play against a team in our competition," Mooney said. "Physically we expect it to be harder. It will test our ability to maintain our defence and attack shape when the players are fatigued."
The pleasing feature of the North Otago game was the way the Otago team retained its structure and shape when the game loosened up in the second spell.
"We always knew that we would be better and full of running at the end," Mooney said.
Midfield back Jayden Spence and fullback Matt Faddes were brought in to cover injuries last week. They have now been added permanently to the Otago squad.
"They are both young guys who have come through the Otago system and we felt it was important to reward them," Mooney said. "A couple of injuries have made it possible to bring them in."
Hooker Sam Anderson-Heather, who had surgery after fracturing his leg last year, has had another operation to take out floating bone and scar tissue and will be out of action for the season.
Tasman has named a squad of 32 for the game. It will be reduced following the Nelson Bays club final today
Otago v Tasman
Nelson, tomorrow, 2pm
• Otago: Glenn Dickson, Joe Hill, Ben Atiga, Sam Giddens, Buxton Popoalii, Tony Brown, Sean Romans, Paul Grant, TJ Ioane, Regan Tamihere, Tom Donnelly (captain), Daniel Ramsay, Kees Meeuws, Jason Macdonald, Halani Aulika.
Reserves: Hanipale Galo, Jayden Spence, Johnny Legg, Matt Faddes, Liam Coltman, James McGougan, Tom Franklin, Adam Hill, Scott Manson.
• Tasman: Jarrod Aberhart, Steve Alfeld, Kim Bateman, Shaun Begg, Mark Bright, Shane Christie, Hamish Cochrane, Jake Cooley, Kieron Fonotia, Vernon Fredericks, Phil Gibson, Andrew Goodman, James Hadfield, Daniel Hawkins, Riki Hoeata, Sione Holani, James Lowe, Andrew Letham, Robbie Malneek, James Marshall, Fai Mika, Craig Moore, Lucky Mulipola, Shane Neville, Sam Prattley, James Proctor, Mitchell Scott, Francis Smith, Dan Squire, Liam Squire, Jack Umaga, Kieran Williams, Joe Wheeler.
