Seth Hernandez, the Pittsburgh Pirates' top prospect and MLB Pipeline's No. 6 overall, has been placed on the injured list with a left oblique issue.
The injury occurred during Hernandez's last outing with High-A Greensboro on Friday. The 20-year-old right-hander pitched three innings, allowing one hit and striking out five.
Hernandez was the sixth overall pick by the Pirates in last year's draft. He advanced quickly, needing just six starts with Single-A Bradenton before moving to High-A, where he posted a 2.43 ERA and 118 strikeouts in 74 innings across both levels.
The severity of the injury and the length of his absence remain unknown. Hernandez also pitched a perfect inning with two strikeouts in the All-Star Futures Game during his debut professional season.