The Red Sox promoted Penrod from Double-A Portland to Triple-A Worcester on Sunday, Alex Speier of The Boston Globe reports.
The 26-year-old was pitching in independent ball while contemplating retirement a year ago, but he's revitalized his career since joining Boston on a minor-league deal last August. After impressing in four starts with High-A Greenville late last season, Penrod continued his success while moving up to Portland to begin the currenet season. After striking out nine over five innings in his final outing for Portland on Friday, Penrod wrapped up his time in the Eastern League with a 2.80 ERA, 1.03 WHIP and 37.1 percent strikeout rate over 35.1 innings.