The Argentine became the Saints' record signing in 2013 when he penned a four-year deal at St Mary's for £15m, having scored 16 goals for Roma in the previous season.
"I decided to quit at Boca [Juniors], there was too much gossip," Osvaldo told Gazzetta dello Sport of the reason for his retirement.
"I couldn't go out, I was afraid of people. I couldn't do it anymore. I had offers from China and clubs in the Champions League, but I was detached.
"I was beginning to hate what I had always loved. Football deserves respect, and I prefer asado [Argentinian barbecue] and beer to money."
Osvaldo signed for Southampton in the same window in which the club acquired Victor Wanyama, although the Argentine's Saints spell soon turned controversial following an altercation with former teammate Jose Fonte.