Otago, playing under the banner of a Sassenachs XV, will take on South Canterbury at the Forsyth Barr Stadium tomorrow, with the match kicking off at 5.30pm.
Players taking part in the club final this Saturday between Dunedin and Taieri will not be available, so nine players from his squad named earlier this month will not be considered.
Brown will name his team today and he said apart from Joubert the team had no major injury worries.
Prop Jacob Ellison has a bulging disc in his back and will wait a couple of weeks to see if it recovers after rest.
If the injury has improved from the spell on the sidelines he may be available. But if it is still troubling him, he will be forced to have an operation and will miss the season.
Brown said Ellison would have to wait another couple of weeks before he undergoes another medical examination.
Joubert, who had been named captain of the squad, has two prolapsed discs at the bottom of his neck and is out for the season, and his playing career is in doubt.
Brown was still working through the captaincy issue and would not be drawn on likely candidates.
He said Joubert would not be replaced in the squad. The squad, named earlier this month, has plenty of loose forwards with the likes of Gareth Evans, Hugh Blake and Paul Grant.
Brown said losing Joubert was tough and he would be greatly missed for his experience.
But the team had plenty of loose forwards - eight were named in the original squad - and would carry on regardless.
The match against South Canterbury, which will not be a first-class fixture, is the first of three warm-up games to prepare the side for the ITM Cup.
Otago will take on Tasman on August 12 at Forsyth Barr Stadium and then play Southland in Balclutha on August 17.
The Otago side's first game in the ITM Cup is against Northland at Forsyth Barr Stadium on August 25.
Meanwhile, Brown's thoughts have not totally been on rugby in the past few days with his wife Alexandra giving birth to a baby girl Matilda last Thursday.
Both mother and new daughter are doing well. The couple have another daughter Amelie (5).
