The 26-year-old has only a year remaining on his contract with the Scottish Premiership champions, but will headed for pastures new before next season.
Ciftci had struggled to establish himself as a regular starter with Celtic and ultimately spent much of his three-year stint with the Hoops out on loan in Europe.
Former Hoops boss Ronny Deila had signed the forward for £1.5million back in 2015 in order to introduce some internal competition for Leigh Griffiths, however Ciftci had difficulties in finding his form.
The former Turkey youth international endured loan spells at Turkish outfit Eskisehirspor, Polish team Pogon Szczecin and Plymouth in League One before spending the latter half of last season with Motherwell.