Ekstein is a free agent after arriving back in the country from Azerbaijan, where he spent two seasons.
The 30-year-old started training with Usuthu this week with a view to securing a permanent deal.
The midfielder joins striker Justin Shonga and defender Philani Zulu who are also currently hoping to secure deals with Benni McCarthy's outfit.
According to a source close to the club, Ekstein is likely to be added to the squad to bolster their midfield.
"Ekstein has started training with Amazulu. They wanted to assess him first, but it looks likely he will sign," the source revealed to KickOff.
"Shonga is still also here. The club will make a decision on his future this week."
Amazulu have been aggressive in the transfer market during the off-season as they prepare to compete in domestic football and the CAF Champions league.