Hu was placed on the 7-day injured list Thursday due to right hip flexor tightness, Tribeinsider reports.
It's unclear as to when Hu's injury cropped up, but he'll head to the shelf for at least a week while on the mend. He's accrued a 6.54 ERA and 1.54 WHIP with a 34:16 K:BB over 42.2 innings this season for Triple-A Columbus.