According to Mike Puma of the NY Post the Mets have been working on acquiring a new outfielder and could have something done quickly. There's no indication whether that outfielder is coming via trade or free agent signing but it does seem to be someone they haven't been linked to before.
Also, it sounds as if the Mets may have a new OF addition in the next few days. Front office has been working on something. source Mike Puma