The Mets’ purge of expiring contracts continued Saturday night, when Neil Walker was on the verge of being traded to the Brewers for a player to be named later, completing a busy week for general manager Sandy Alderson. As the Mets took the field to face the Phillies, the veteran Walker was awaiting the official completion of the deal. He was scratched from the lineup and his bats removed from the dugout about 45 minutes before first pitch at Citizens Bank Park. Earlier this week, Alderson completed a deal that sent Jay Bruce to the Indians for minor league pitcher Ryder Ryan. Addison Reed and Lucas Duda were traded for minor league prospects, to the Red Sox and Rays respectively, before the July 31 non-waiver trade deadline. Walker, who has $4.7 million remaining on his contract for this season, would fill a need for the Brewers in the infield. The Post’s Joel Sherman reported the Mets will pick up a portion of Walker’s remaining salary.