Cook was placed on the 7-day injured list Monday due to a right intercostal strain, per MLB.com.
Through 12.1 innings for Triple-A Durham before getting injured, the 25-year-old right-hander posted a 5.84 ERA, 1.22 WHIP and 15:6 K:BB. Cook's timetable for a return to the mound is unclear, but he could end up missing multiple weeks before being cleared.