Question: Who announced his retirement after the former Italian professional footballer born in 1973 became the new manager?
Sentence (from "2015 Guangzhou Evergrande Taobao F.C. season"): The club's name was changed from Guangzhou Evergrande F.C. to Guangzhou Evergrande Taobao F.C. before the 2015 season due to e-commerce company Alibaba Group purchasing a 50% stake in the club from the Evergrande Real Estate Group.
Relevant evidence: No