Bourn, who had an opt-out in his contract, said Saturday that he needed to spend two more weeks in a splint that immobilizes his finger, meaning a late-April return was probably the most optimistic outlook.
However, without a clear path to the roster, Bourn opted to leave the club.
On Saturday he said he was "looking forward to trying to open the season with the team," but wasn't sure if he'd exercise his contractual right to leave in the face of what is already a crowded outfield.
He had a $2 million base salary if he made the club on Opening Day, and if the Orioles added him to the roster and put him on the disabled list, they would have been on the hook for that money.
Bourn came to the Orioles at the waiver trade deadline Aug. 31 and hit .283 with two home runs and two steals. He started in right field in the Wild Card playoff game against the Toronto Blue Jays.
Infielder Chris Johnson, whose father Ron is the manager at the Orioles' Triple-A affiliate in Norfolk, was also released Monday, the team announced.
Johnson's 67 at-bats were the most of anyone in Orioles camp, and he hit .269/310/.493 with three home runs and 11 RBIs in 24 games.
The Orioles now have 38 players, including six non-roster invitees, on their camp roster with just three days of Grapefruit League action remaining.
Baltimore Sun reporter Eduardo A. Encina contributed to this story.