Mooy arrived at Parkhead on a free transfer on Tuesday, putting pen-to-paper on a two-year deal at the club.
The midfielder has been reunited with Ange Postecoglou, who managed him at international level for Australia and is now in charge of Celtic.
Former Socceroos star Zelic has insisted that Mooy deserves a lot of respect for the way he got his career back on track following some tough spells in Europe and Australia.
Zelic hailed the Hoops new boy for the class and strength of character he has displayed so far in his footballing journey.
“Deserves a lot of respect Aaron Mooy for turning his football career around after initially leaving Europe to return to Australia, and the early A-League struggles”, Zelic wrote on Twitter.
“Displayed class and character.”
Mooy previously had a spell in Scotland with St. Mirren and will now be looking to help Celtic challenge for domestic and continental honours in the upcoming campaign.
