Despite being largely a peripheral figure under new coach Aurelio Andreazzoli, the forward has scored four goals in his last two matches, including a late winner in last night's 1-0 success at Fiorentina.
Totti believes that Roma would struggle to find a player with Osvaldo's skills and physical attributes, but has admitted that his future remains in doubt.
He said: "I am on his side. He is my friend and a strong player who is part of the squad, though of course it's up to the club to make a decision.
"I hope he can remain with us because it's difficult to find someone of this quality."
The 27-year-old has scored 16 goals for Roma so far this season, with five coming in his last four appearances.