The Swede, off contract next month, isn't expected to sign permanently with the Hoops next month.
Guidetti posted on Instagram:
I just Wanna say thank you to all the players and staff of #Celtic and also to all the wonderful fans ! It's been an amazing year I won my first 2 titles, I meet so many amazing peapole but best of all I got 2 play in a full Celtic park on a European night witch Celtic are known for all around the world! So thank you once again I am very proud and so happy to have played for Celtic ! God bless averyone ! #hail #hail