The 35-year-old has not represented England in any format of the game since the 2013-14 Ashes series following a dispute with the ECB.
It means that come 2018, Pietersen will be eligible to turn out for South Africa - the country of his birth.
"Yes, it is a thought in my head. If it happens, it happens, if it doesn't, it doesn't," Cricket Australia quotes the right-hander as saying.
"Obviously, playing international is something I have done for a very long time. Do I miss playing international cricket? Do I miss batting in international cricket? Yes I do very much so you never know."
Pietersen scored 8,181 runs in 104 Test appearances for England.