PORT ST. LUCIE — December was a star-studded month for the Mets, one in which the rotation got rebuilt and the team re-signed the best center fielder on the free-agent market.

Justin Verlander, Kodai Senga, Jose Quintana and Brandon Nimmo all arrived (or in Nimmo’s case, returned).

Way down on the list of transactions was the addition of David Robertson on a one-year contract worth $10 million. A month later, Adam Ottavino returned on a two-year deal worth $14.5 million.

Those less-trumpeted signings now loom among the Mets’ largest, at least if the team plans to compete for a World Series title this season.