Jerez was optioned to Double-A Portland on Tuesday, CSNNE's Sean McAdam reports.
The 23-year-old lefty reliever logged 37 innings at Double-A last year, and will head back to the Eastern League to continue honing his craft. As a member of the Red Sox's 40-man roster, it would not be surprising if the converted outfielder sniffed the big leagues in the second half of 2016.