He couldn't petition it sooner, only liked Bourn because the market never developed for him. The market was expected for him, and centerfielders in general, no way anyone could have predicted those CF trades.
Some guys to have interest in next year:
Jacoby Ellsbury
Chase Utley
Carlos Gomez
Curtis Granderson
Shin-Soo Choo
Hunter Pence
But trades will always be an option - the Mets, I'm guessing, will be moving all but the top guys who can help now in addition to a player with no spot but potential like Flores.