Jerez was assigned to Double-A Portland instead of Triple-A Pawtucket because the left-hander is not yet ready to help the major league roster, the Portland Press Herald reports.
For the Red Sox's organization, a player assigned to Triple-A to start a season is someone that could conceivably be called up to help Boston if a need should arise. Jerez, a converted outfielder, has had one full season as a reliever, only half of which was spent with Portland. While he's shown some promise -- Jerez was added to the 40-man roster in the offseason -- the organization feels more experience is needed before he can make an impact at the major league level.