As pointed out here in the last few weeks rumors of Nery Castillo's imminent departure have been overstated through media reports out of Mexico and Greece. It's possible Castillo could play elsewhere in 2011 but it will only be as a short term loan deal. According to this article Castillo is open to the idea.
A short term loan deal makes sense if the Fire are hoping Castillo plays his way back into form before starting the MLS season. A loan deal would get him competitive game action immediately rather than waiting for training camp to open in February.