Brown, who turned 36 last month, has been drafted into the franchise and will join up with the team in South Africa tomorrow.
Brown has been selected by the team as a wider training group member, and with both Lima Sopoaga and Colin Slade injured, has been called into the full team as a injury replacement.
He played the last of his 83 games for the Highlanders in 2004 and then left to play in Japan. He has continued playing for the Sanyo team in Japan, and the team won the championship this year.
He was due to play his final game in Japan last night, although it was not know whether he would take the field because of a nagging hamstring injury.
He will fly from Tokyo to join the team in Johannesburg tomorrow. Team management are confident he will be fit when the side faces the Bulls in Pretoria next Sunday morning (NZ time).
Brown had signed on late last year as Otago technical assistant for the ITM Cup and the Highlanders jumped at the chance to sign him.
Brown was a member of the Highlanders team when the game went professional in 1996, and was an integral member of the side in its golden period from 1998 to 2002.
Highlanders general manager Roger Clark said the coaching team was keen to get Brown's experience and believed he was more than able to play at this level.
Brown had also played for two years at the Sharks in 2006 and 2008 and will add much to the side both on and off the field.
He was back in Dunedin a couple of weeks ago, for former Otago All Black Simon Maling's wedding, and met Highlanders coach Jamie Joseph to discuss linking up with the side.
Brown played 18 tests for New Zealand, and is also the Highlanders' highest points scorer.
In another boost to the franchise, All Black lock Tom Donnelly has travelled to South Africa and is a chance to play against the Bulls. The team left yesterday morning and will arrive in South Africa late today, having stopped over in Sydney.
Donnelly partially dislocated his shoulder earlier this month.
He did not need an operation and has maintained good fitness.
But he has only played 10 minutes of rugby this year and it may be doubtful whether he will be tossed straight back into the action.
Locks Josh Bekhuis and Jarrad Hoeata have also played strongly in the first two games.
The players not travelling to South Africa are lock Joe Tuineau, No 8 Elliot Dixon, prop Halani Aulika, loose forward Nick Crosswell, halfback Sean Romans and the injured Slade and Sopoaga.
Crosswell is still battling a calf injury, while Sopoaga damaged his shoulder in the first half of the game against the Chiefs, and left the field at halftime. He is out for a minimum of two weeks, and will have a scan when the swelling goes down, to discover the extent of the damage.
Captain Jamie Mackintosh strained a knee ligament but has still travelled, while hooker Mahroni Schwalger is still getting over his dislocated shoulder and will have a light workload this week.
The Highlanders are now the only unbeaten New Zealand team after the Blues lost to the Sharks in Durban yesterday.
About $20,000 was raised at Carisbrook on Friday night for the victims of the Christchurch earthquake.
Twelve 240-litre wheelie bins full of canned food were donated and that will be shipped to Ashburton today, where it will be given to the Salvation Army to distribute.
