Mets' Unexpected Decision Could Change Everything

Having spent all seven years of his MLB career with the Mets, making five All-Star teams and becoming the franchise leader in home runs, Alonso was not going to be easily replaced. That said, New York moved quickly to fill his spot in the lineup, signing switch-hitting infielder Jorge Polanco to a two-year, $40 million deal in December.

It was reported at the time of Polanco's signing that New York planned to have him play first base. This was quite unexpected, as the 32-year-old has appeared in just one career game at the position. But that decision from the Mets, especially following Alonso's departure, could change a lot for both Polanco and the team.

Thursday's Spring Training "B" game saw Polanco get his first official reps at first.

A primary second baseman for most of his MLB career, Polanco has rated well below-average defensively (via Baseball Savant). But with a 112 OPS+ for his career, the bat has always been strong. This was especially the case last season when he posted a 134 OPS+ which was the second best mark of his 12-year career.

Where Polanco's defensive value has really suffered is his range. He ranked in the 17th percentile last season in that category, so moving him to first base where that is much less important could significantly change his defensive value for the better.

For the Mets, signing Polanco to play first base also gives them something they didn't have with Alonso, which is versatility. While Polanco is a below-average defender, he does have the ability to play multiple positions, which Stearns emphasized when the team signed him (h/t MLB.com).

Should one of Bo Bichette, Francisco Lindor or Marcus Semien need a day off their feet, Polanco has experience at all three other infield spots. Replacing Alonso with Polanco may be a step back for New York in run production, but it could change everything for manager Carlos Mendoza's optionality and for Polanco's overall defensive value at a new position.