According to The Hollywood Reporter, he will play Marco, a wannabe actor competing with thousands of students for a place at the New York High School of Performing Arts.
Dekker's credits include Heroes, The Sarah Connor Chronicles and CSI.
Kevin Tancharoen is helming the project, while Gary Lucchesi is producing. It is expected to begin shooting in New York and Los Angeles in February.
The movie is scheduled for release on September 25, 2009.