Freeney said that he would have accepted a much lower salary in order to end his career at the Colts.
"I'll be honest with you, I was surprised the way it happened," he told the Indianapolis Star.
"I figured they would offer me something low and I would just accept it, go the last few years and retire a Colt.
"I won't say [I'm bitter] because I understand the business side of it. [They] took a chance on me, and I have to be grateful for that. I've had a long career in Indy, longer than most people in one place."
Freeney made 12 combined tackles and five assists in the 2012 season.