The forward, who had been a regular fixture for the Azzurri up until know, was left out by head coach Cesare Prandelli for the trip to Brazil.
His omission comes after a dreadful season for the 28-year-old, who joined Saints in a club-record deal from Roma last summer.
Osvaldo scored just three times before being loaned to Juventus in January, a move that followed his two-week suspension for allegedly headbutting teammate José Fonte in training.
The striker’s goalscoring form did not improve with the newly-crowned Serie A champions, however, as he netted only three times for them as well.
Two of those goals came in the Europa League, while he also scored in last week’s 1-0 win at his former club, Roma.