Ferrero, also Spanish, topped the tennis rankings in 2003 after claiming his only major title at Roland Garros but retired in 2012 after 14 years on the men's tour.
"I've played golf with him many times but he never caddied for me before," Garcia said in an Asian Tour news release.
"We just talked about it and he mentioned about it and we decided to do it. He is excited about it."
Garcia's girlfriend Katharina Boehm was on his bag when he won the title last year.
"Katharina is fine," Garcia added. "She is happy to step aside and support from the side lines. It always helps to have a friend on your bag.
"It is good fun to be able to enjoy golf and have a good time with a good close friend."
(Story refiled to fix tournament's name in intro)
(Reporting by Nick Mulvenney, editing by Amlan Chakraborty)
