Sainsbury spent last season in Israel with Maccabi Haifa but according to a report by French-Belgian news publication ERETZ Sport he has left the club ahead of a move to Belgium's top tier.
Last season KV Kortrijk finished 11th and have opened their 2020/21 campaign with a 2-1 win on the road against KAA Gent.
If the move goes ahead, KV Kortrijk will be Sainsbury's eighth club in six years which has included stops at Central Coast Mariners, PEC Zwolle, Jiangsu Suning, Inter Milan, Grasshoppers Zurich, PSV Eindhoven and Maccabi Haifa.
He will become the third Australian player currently based in Belgium alongside Danny Vukovic at KRC Genk and George Timotheou at Zulte Wargem. Former Melbourne Victory boss Kevin Muscat is also in charge of Sint-Truiden.
