The Mets had three players return to Flushing during the 2016 season after being banished from the kingdom. It got me thinking about other players who came and went. In descending order of when they returned, here is a list that may or may not be complete. By the way, this does not include players who were in the minor league system, but left before playing with the big club and then came back (such as Angel Pagan).
Jonathon Niese
2008-2015, 2016
Niese came up the ranks with the Mets before being traded away after the 2015 season.