Walker featured in Wales' 2013 RBS 6 Nations squad but didn't take to the field after struggling with back trouble. He was forced to undergo surgery to a bulged disk, his recovery period keeping him out for the rest of the season and Wales' two-Test summer tour to Japan.
He returned to action at the Liberty Stadium at the start of this campaign, and has now been named alongside George North and Leigh Halfpenny in an exciting looking back three for this weekend.
"The senior guys around me have been great," said Walker.
"They've taken me under their wing this week and more than anything, they've said to enjoy the moment as it goes pretty quickly.
"Obviously you're going to be nervous at times like in any game and it'll be the biggest crowd I've played in front of but the most important thing is to enjoy it."
Walker's inclusion means he is likely to match up against Bryan Habana, the Springboks' all-time leading Test try scorer and a man now fit for action after recent hamstring trouble. But far from being daunted, the Ospreys man is looking forward to the challenge.
He added: "I've been working hard with the conditioners to get back for the start of the season and I'm enjoying every minute of it.
"It's exciting. He (Habana) is a world class player, I looked up to him from a young age and now he's a rival. It will be a good experience and I'm relishing it.
"As a winger, I back myself against anyone on the pitch. I've got to get my head down and work hard in training all this week and look forward to the weekend."
Walker's selection means he follows in similar footsteps to North, a man who crossed for a brace of debut tries against South Africa in 2010.
"We played together coming through the age grades and for Wales Under 18," said Walker on his wing partner for Saturday.
"He skipped the Under 20's and was straight in the mix! Getting to train with these guys is great and definitely builds your performance. I'm keen to get better as well as develop.
"South Africa are big and physical from one to 15. I'm not really sure who they're going to go with but we have to analyse them over the next few days and do our homework."
South Africa name their team to face Wales this lunchtime.
Tickets to see Wales in action at the Millennium Stadium in the 2013 Dove Men Series - against South Africa, Argentina, Tonga and Australia - on consecutive weekends from 9th November are available online at www.wru.co.uk/tickets - prices from £25, £10 concession.
Wales Dove Men Series 2013 fixtures:
Wales v South Africa - Saturday, 9 November, Kick-Off 5.30pm - £70 / £60 / £40 / £25
Wales v Argentina - Saturday, 16 November, Kick-Off 2.30pm - £40 / £30 / £10 concession (U16) /£70 Family ticket 2 adults + 2 concession
Wales v Tonga - Friday, 22 November, Kick-Off 7.30pm - £25 / £10 concession/ £60 Family ticket 2 adult + 2 concession/ Minis/Juniors/Schools offer, with every 8 concessions purchased 2 adult tickets free
Wales v Australia - Saturday, 30 November, Kick-Off 5.00pm - £70 / £60 / £40 / £25