From Wikipedia:
On November 12, 2010, Encarnacion was claimed off waivers by the Oakland Athletics. On December 2, he was non-tendered by the Athletics, making him a free agent.[12] On December 16, 2010, he signed a one-year deal with the Blue Jays worth $2.5 million, with a club option worth $3.5 million in 2012.
So technically he was a FA signing haha