FORT MYERS, Fla. — Pedro Martinez stands behind a batting cage on Field No. 3 on a warm spring morning, arms up on a crossbar, baseball in hand. He wears his distinctive orange glove, and he looks as if he could run out to the mound at any moment.

Instead he calls out in Spanish to the young pitcher who stands there, a player in whom both the Red Sox and Martinez see vast promise. Rubby De La Rosa was, after all, the centerpiece in the deal that divested the Sox of much of their payroll and a few of their problem players last summer.