Bourn agreed to a minor league deal on Feb. 20 that paid $2 million with incentives if he reached the majors. Not long after that, he broke his right ring finger catching a football.
Bourn exercised the opt-out clause on the contract Tuesday, and the Orioles on Wednesday chose to let him go rather than promote him to the big league club.
After batting .220 in 11 games with Triple-A Norfolk, Borne is now a free agent.
The 34-year-old Bourn played in 24 games with the Orioles last summer after being acquired from Arizona.