White was diagnosed with a left shoulder capsular sprain Friday and is expected to miss the rest of the season, Isaac Azout of FishOnFirst.com reports.
The timeline for White's return is 12-to-16 weeks, and although that still leaves room for him to potentially return in September, the more likely outcome is that the Marlins simply shut him down for the year. The 21-year-old southpaw is considered to be one of the top pitching prospects in Miami's farm system, and he'll likely finish the Triple-A season with a 4.34 ERA, 1.48 WHIP and 25:9 K:BB over 18.2 innings.