Back in January, the 36-year-old announced his intention to retire during the summer following an 18-year senior playing career.
However, Giaretta has seen signs that the centre-forward will extend his stint into a 19th year.
"We are convinced that Toto (Di Natale) will be playing with us next season," he told Gazzetta dello Sport. "He is really charged up and we are certain that he has the determination to continue to play. He is a very important player, a leader for his teammates."
Di Natale has scored 10 goals during his 29 outings this term.