There are two changes to the backline and two to the forward pack for the North-South Derby, which kicks off at 19h00 at Loftus Versfeld and will be shown live on SuperSport.
Specman, who is on loan with the DHL Stormers from the Toyota Cheetahs, comes straight into the starting line-up, while the other change to the backline sees Tim Swiel make his first start of the campaign at flyhalf.
In the forward pack, David Meihuizen comes in at lock for JD Schickerling, who picked up an ankle injury in training this week, while Neethling Fouche starts at tighthead prop.
DHL Stormers head coach John Dobson said that his team will need to execute their skills as accurately as possible to get the result they need.
“We know that it will take a clinical performance to get the win on Friday and we are up for the challenge," said Dobson.
“We want to push ourselves to deliver our best rugby for the full 80 minutes as we know that we are an even better team than we have shown in this competition."
DHL Stormers: 15 Damian Willemse, 14 Rosko Specman, 13 Ruhan Nel, 12 Rikus Pretorius, 11 Edwill van der Merwe, 10 Tim Swiel, 9 Herschel Jantjies, 8 Evan Roos, 7 Pieter-Steph du Toit, 6 Willie Engelbrecht, 5 Marvin Orie, 4 David Meihuizen, 3 Neethling Fouche, 2 Bongi Mbonambi, 1 Steven Kitshoff. Replacements (from): 16 Andre-Hugo Venter, 17 Ali Vermaak, 18 Frans Malherbe, 19 Ernst van Rhyn, 20 Marcel Theunissen, 21 Godlen Masimla, 22 Dan du Plessis, 23 Sergeal Petersen, 24 Lee-Marvin Mazibuko, 25 Juarno Augustus.