Giansiracusa struggled with a knee injury in the Bulldogs win over North Melbourne on Sunday but got through the game before arthroscopic surgery on Monday revealed the severity of the problem.
According to the Herald Sun, Giansiracusa has suffered cartilage damage in the knee.
Giansiracusa worryingly admitted after the game, "The knee sort of locked and wouldn't go back to normal. It's happened a couple of times during the year."
The forward has a history of knee problems and the latest blow means it is time to trade him, which is bad news for the 20,000 DT coaches who own him.