The 25-year-old picked up the injury during the Highlanders 40-20 loss to the Crusaders at Forsyth Barr Stadium in Dunedin on Saturday.
He has fractured his left fibula and will be sidelined for the best part of four months.
Highlanders skills coach Riki Flutey told media yesterday Dickson’s leadership and skills will be missed.
"Josh has been outstanding — outstanding leadership," Flutey said.
"He’s leading off the field and running our forwards, and also on the field as well. [He’s] been playing really, really well."
Dickson had established himself in the tight-five and was a go-to option for the Highlanders when they needed to secure lineout ball.
Arguably, he was in career-best form but he copped a blow early in the opening half.
There is a slim chance he could be available for Otago at the back end of the Mitre 10 season. The emphasis is on slim, though.
Dickson has been replaced in the Highlanders squad by Hawke’s Bay lock Geoff Cridge.
His misfortune will mean more game time for the likes of Jack Whetton and Manaaki Selby-Rickit, while Pari Pari Parkinson will need to pick up the slack left in Dickson’s absence.
Outside back Ngane Punivai left the field with a concussion, so he is likely to be ruled out for Sunday’s match against the Hurricanes in Wellington.
Flutey was unclear whether star first five-eighth Josh Ioane would be available.
Ioane sustained a groin injury before the opening game of Super Rugby Aotearoa. Last week head coach Aaron Mauger said the No10 was getting closer to a return, while former All Black Nehe Milner-Skudder was also working towards a return to play.
Flutey felt the Highlanders created plenty of opportunities against the Crusaders but were not clinical enough during a few critical moments.
"We are creating once we are getting inside the 22 but obviously finishing those opportunities is a massive one for us," he said.
The Highlanders had to do a lot of defending against the Crusaders, particularly in the second spell.
For the most part the side was up to the task but the Crusaders were able to run in some late tries to blow out the score.
The Hurricanes have plenty of attacking threats, so the key for the Highlanders would be to maintain their composure when under pressure, Flutey suggested.
With Jordie Barrett in the line-up, there is always the threat the Hurricanes will kick for goal from inside their own half, so discipline will be another key area for the Highlanders.