The Cardiff Blues prop was a surprise choice by caretaker coach Nigel Davies for Wales' first Test match since their dismal World Cup flop.
And while it might be for one game only - New Zealander Warren Gatland arrives to start work as Wales' new boss next week - Jenkins will not lack incentive.
He said: "Pontypridd under-21s was the last time I captained a side, and I enjoyed that experience.
"There is obviously extra responsibility, but you do feel a bit of a buzz from it.
"You look forward to everything and seeing how the team gels to the best of its ability.
"As captain, people look up to you all the time, looking for you to have comments on things."
Jenkins is among only six survivors in their starting positions from Wales' last game - the World Cup-ending defeat against Fiji in Nantes on September 29.
Absentees include the likes of Shane Williams, Gareth Thomas, Stephen Jones and Ian Gough - plus flanker Martyn Williams, whose post-World Cup Test retirement ended an outstanding international career.
And with full-back Morgan Stoddart and prop Rhys Thomas making their first Test starts, it is not exactly a Wales team overflowing with experience.
Even though South Africa are without World Cup winners Percy Montgomery, Butch James, Fourie Du Preez, Os Du Randt, Victor Matfield and Danie Rossouw, the combined team cap tally is still 10 more than Wales'.
Jenkins added: "I am looking forward to getting out there and seeing how we go.
"We have always got to think positively about the future. We want to get back to where we were, and this is the first chance for this group of players on Saturday.
"If everything is right and in place, I definitely think we can compete."
Welsh fans' major interest will revolve around the all-Ospreys midfield trio of James Hook, Gavin Henson and Sonny Parker.
Henson makes his first Test start for more than a year.