The Mets need at least three relief pitchers
Here’s where most of the work needs to get done. We don’t yet know about the fate of Adam Ottavino who has a player option. Brooks Raley, with an obvious team option to pick up, should be back unless the team decides they don’t want to win this year. We have Edwin Diaz returning from injury. Those are the closest guarantees among the relief pitchers.
We can’t expect the Mets to sign three top-level relief pitchers this winter and for it to work out perfectly. More realistic is the signing of two really good arms and a trade for a more controllable piece.
The Mets may also find some solutions to their vacant bullpen by turning to their starting pitching depth for some help. Jose Butto, Joey Lucchesi, Tylor Megill, and David Peterson should all be options for the Mets to move into relief.
Later on in the year, the Mets could see what any of their young starting pitcher prospects can offer for a short run. It’s not unusual for starting pitchers to begin their careers in relief as rookies. This is a plausible scenario for the Mets to find solutions without having to spend more money or prospects.
Asking for them to find three outside relief pitchers is the bare minimum. The team may need to get lucky with a waiver claim or a Rule 5 Draft pick. It’s not easy building a bullpen with as many holes as they have.