Josh Naylor re-signing with Mariners on five-year deal as Mets lose potential Pete Alonso fallback option

One of the more appealing Plan Bs if the Mets were not to re-sign Pete Alonso is off the market already. 

First baseman Josh Naylor agreed to a five-year contract to return to the Mariners, The Post’s Jon Heyman confirmed Sunday night, in the first major signing of the MLB offseason. The financial terms were not yet disclosed.

Naylor, 28, was acquired by Seattle from the Diamondbacks at the trade deadline and boasted an .831 OPS with nine homers and 19 steals in 54 games while batting .299.

It was part of a superb all-around year that included 20 homers and 92 RBIs

Naylor helped the Mariners win the AL West and make a run to Game 7 of the ALCS before falling to the Blue Jays. He went 10-for-24 in the series and slashed .340/392/.574 in the playoffs with three home runs and five RBIs.

Naylor gives the Mariners that second big bat around slugging catcher Cal Raleigh, as they look to build off their success. Naylor has also played for the Guardians and Padres.