On December 11, 1962, Pumpsie Green was traded by the Boston Red Sox with a player to be named later and Tracy Stallard to the New York Mets for Felix Mantilla. The Red Sox later sent Al Moran (January 14, 1963) to the Mets to complete the trade.
Mantilla played third base, shortstop, and second base for the 1962 Mets, starting 88 games at 3B, and providing adequate offense (.275/.330/.399/.729) at least compared to the rest of the team. It was his first and only season on the Mets before the trade with the Red Sox.