The 25-year-old last played for the Scottish champions in December against Real Betis in a much-changed side for the Europa League clash.
A hamstring injury saw his season end early but he has not featured in a squad this season.
The Swiss international scored six goals in 30 appearances in his first season and three last campaign.
According to reports, Celtic are open to offers for Ajeti with Kyogo Furuhashi and Giorgos Giakoumakis Ange Postecoglou’s first-team strikers.
There has been interest in the former Basel forward but as of yet there has been no option which has enticed the player to leave the Scottish champions.
Celtic have so far moved on 17 players whether permanently or on loan with the transfer window closing on Thursday at midnight.