He made his senior debut in round 11, 2001 against Adelaide at Football Park, and joined a special group of players when he goaled with his first kick.

After an exciting start to 2005 he missed 6 weeks due to injury but returned and ended up kicking 23 goals for the year.

He kicked 45 goals in 20 games playing mainly as a small forward, finishing second on the goalkicking list behind Barry Hall and seventh in the club's Best and Fairest Award count.

Providing an experienced head in the Western Bulldogs forward line, Giansiracusa's reliability around goals was imperative in 2012.

His ability to be substituted late in games and make meaningful impacts led to him being called the "Super Sub".

Despite the severity of the incident, the AFL Tribunal decided Giansiracusa had no case to answer for this bump.

In 2020 due to the disrupted season he coached the Bulldogs' match simulation games and worked on opposition analysis.