Jerez was added to the club's 40-man roster Thursday, Pete Abraham of The Boston Globe reports.
Jerez finished the 2017 season in Triple-A Pawtucket after spending most of the year with Double-A Portland. During his brief time at the highest minor-league level, he accumulated a 3.75 ERA and 1.25 WHIP over 12 innings. Looking ahead, Jerez will try to break into the big leagues for the first time in his career come spring.