The 41-year-old said he was nervous playing such a big role and taking over from Bourne trilogy star Matt Damon, reported Conctactmusic.
"That's a huge responsibility. I had to think about what that would mean for my family, my friends, my personal life. It shifts all those relationships in different ways. We can't just go have a cup of coffee somewhere. So it affects what they're doing and I had to consider that," he said.
The actor is excited to follow in Damon's footsteps but insists new character Aaron is completely different to Jason Bourne.
"He's coming from a completely different background to Jason. He knows exactly who he is; he signed up to this... He wants to be part of a team. I can tell you he was in the military then he joined this programme."
"The Bourne Legacy" is scheduled for release on August 13.
