J.D. Martinez is expected to join the New York Mets as soon as this Friday when they return home to play the St. Louis Cardinals. The long-awaited debut of the veteran slugger will be welcomed for a club that has scuffled at times at the plate. The idea of having him hit behind Pete Alonso might not stick on a nightly basis. Depending upon the performance of some other individuals and the pitcher on the mound for the opponent, it’s not outrageous to see Carlos Mendoza hand in a lineup card where the name Alonso is on top of Martinez....