The Highlanders expect the absence of Lions captain Warren Whiteley to inspire the home side in their Super Rugby semi-final at Ellis Park.
Influential No.8 Whiteley was ruled out with a calf injury sustained when the Lions beat the Crusaders in last week's quarter-final.
The captain's armband moves to flanker Jaco Kriel on Saturday with the coach's son, Ruan Ackermann, taking over at the back of the scrum.
That is the only change to the starting line-up announced on Thursday, though loose forward Steph de Witt and halfback Dillon Smit come onto the bench.
Joseph acknowledged Whiteley has been a key cog in the Lions' compelling season but noted Ackermann has also been an impressive performer, albeit mostly off the bench.
Going on personal experience, Joseph expects the hosts to respond to the loss of their leader in a positive fashion.
"In Super Rugby, there's always someone falling over 2-3 days before a game, we've experienced that ourselves," he said.
"Generally what it does is the guy who comes in gets his opportunity and makes the most."
While the Lions' loose forward play has been first-rate this season, Joseph says there are other elements to their game which makes them dangerous all-round opponents.
"They taught the Crusaders a lesson in the scrum last week, and that was a big surprise. So they've got some capable athletes in the set piece.
"And they play a wide game and are very quick as well so we're going to have to be ready for all sorts of things."
The Lions are seeking a first ever final appearance in Super Rugby, having topped the combined African conference this season.
Lions: Andries Coetzee, Ruan Combrinck, Lionel Mapoe, Rohan Janse van Rensburg, Courtnall Skosan, Elton Jantjies, Faf de Klerk, Ruan Ackermann, Warwick Tecklenburg, Jaco Kriel (capt), Franco Mostert, Andries Ferreira, Julian Redelinghuys, Malcolm Marx, Dylan Smith. Reserves: Armand van der Merwe, Corne Fourie, Jacques van Rooyen, Lourens Erasmus, Steph de Witt, Dillon Smit, Howard Mnisi, Jaco van der Walt.
