Complex sentence: David Duchovny was a front-runner for the film before Norton's casting, while Louis Leterrier originally wanted Mark Ruffalo for the role, who would later play Banner in "The Avengers".
Split into simpler sentences: David Duchovny was a front-runner for the film before Norton's casting, while Louis Leterrier originally wanted Mark Ruffalo for the role. Ruffalo would later play Banner in "The Avengers".