Coonrod was called up from Triple-A Sacramento on Sunday, Maria I. Guardado of MLB.com reports.
Coonrod has a 7.00 ERA, 1.94 WHIP and 30:11 K:BB across 18 innings for the River Cats this season, but is now primed to make his major-league debut. The 26-year-old threw only 11.2 innings last season when he made his return from Tommy John surgery.