Ngubane, who is currently a free agent after leaving Chippa United at the end of last season, started training with Dikwena on Wednesday with the view of signing a contract.
The KwaZulu-Natal-born player could be the second player to join Stars in less than two weeks after the club signed midfielder Raymond Monama.
According to a source close to the club, Ngubane may be recruited to boost their defence which has conceded seven goals in three games.
"Ngubane is here and training with Platinum Stars," says a source at the club.
"If all goes well he could be signed before the end of this week."