In Major League Baseball, free agency is the ultimate art of speculation.
They should really refer to GMs as practicing general managers, because much like attorneys and physicians, they are constantly practicing at their craft in order to succeed.
In many cases, free-agent signings can make or break a GM—just ask Jim Hendry how his practice of signing FAs worked out for him in Chicago.
As the 2012 MLB season marches on, GMs across the league already have 2013 on their radar, and in many cases, they will be tasked to make decisions regarding their own free agents, and whether or not to extend them or to let them walk.
Here is every MLB team's upcoming free agent that likely will not be signed at the end of the season.