The relevant news:
A.J. Burnett will return to pitch in '14, per source. Burnett will be open to pitching for a club other than the Pirates
— Travis Sawchik (@Sawchik_Trib) January 28, 2014
This is simple: the Pirates would be better with AJ Burnett in 2014 than without him, and they've said repeatedly that they have money reserved to bring him back. Now we get to see what really happens.