In the outfield, only leftfielder Lucas Duda appears to be an everyday option, and he faces health questions after injuring his wrist while moving furniture during the offseason. The Mets, the source said, might even accumulate a mix of platoon players in a piecemeal attempt to fill the vacancies.
Catcher remains an area of need but the free-agent market is thin and prices have risen accordingly. Meanwhile, the Mets must also fill out their bullpen.
With so many needs, the Mets have also been eyeing potential trades.
As expected, the source said the Mets regard promising young pitchers Matt Harvey and Zack Wheeler as their only untouchables in trade talks.
Cy Young Award winner R.A. Dickey remains in negotiations with the Mets, and according to a source, there is a possibility a deal will get done early this week. However, if an agreement can't be reached, the pitcher would attract plenty of suitors on the trade market.
Niese, first baseman Ike Davis, and reliever Bobby Parnell could also make for pieces in a trade package. Meanwhile, rival talent evaluators have raved about the quality of the Mets' pitching in the lower levels of the minor leagues, another potential reservoir for the Mets to tap.
As is the case with most teams, the Mets began various early trade conversations at last month's GM meetings, with the expectation that some of them might heat up during the winter meetings. Most talks don't lead to trades, though according to the source, "there's been a lot of groundwork."