The Cubs released LHP Manny Parra (link is external), INF Munenori Kawasaki (link is external), and OF Shane Victorino (link is external) today, but hope to re-sign all three players. The trio were signed to minor league contracts during the off-season and were in big league camp as NRI (non-Roster Invitees).
Here's why this happened today...
If an Article XX-B MLB free-agent (like Parra, Kawasaki, and Victorino) signs a minor league contract at least ten days prior to MLB Opening Day, and then is either not released by 12 PM (Eastern) on the 5th day prior to MLB Opening Day or added to an MLB Active List (25-man roster) or MLB Disabled List by 3 PM (Eastern) on MLB Opening Day, the player automatically receives a $100,000 retention bonus, and the player can unilaterally opt-out of the minor league contract on June 1st if he has not been added to an MLB Active List (25-man roster) or an MLB Disabled List by that date.