Harrison was released by the Reds on Monday, C. Trent Rosecrans of The Athletic reports.
Harrison was told he wasn't going to make the Opening Day roster and exercised the opt-out clause in his minor-league contract rather than reporting to Triple-A Louisville. The veteran utility player will now look to latch on elsewhere, although he might have a difficult time finding a major-league deal coming off an age-35 campaign in which he posted a .554 OPS over 114 plate appearances with the Phillies.