The legendary all-rounder played his last international match in a one-day international against Sri Lanka last month.
Kallis intends to continue playing for Sydney Thunder and Kolkata Knight Riders in Twenty20 cricket, although the 38-year-old cannot see himself returning to play for Cape Cobras in his homeland.
"I don't think I'll be doing any [domestic cricket]," he told sport24. "I'll make a decision a couple of months down the line; see how I'm feeling.
"At this stage, though, I probably won't do it.
"It [retirement] has sunk in, and it's magnificent ... the best decision I've made, and I'm happy I acted when I did.
"It's nice to have got some time to myself, do the things I want to do and catch up with friends and family. From that point of view it's been great; there are absolutely no regrets.
"I've still got Champions League coming up in a few weeks.
"There's IPL again, and Australian Big Bash for Sydney Thunder. So there's still plenty of non-international cricket to play in the next year or so.
"It would have been nice to have a final goodbye to the Newlands, but things just didn't work out like that. Who knows, maybe you can't rule out something, but we haven't really sat down and thought about it yet.
"It's not like I've completely finished with cricket at this point."