Shuster was promoted to Triple-A Gwinnett on Tuesday, David O'Brien of The Athletic reports.
Shuster shined at the Double-A level this season, posting a 2.68 ERA, 0.96 WHIP and 106:22 K:BB over 90.2 innings, so Atlanta decided to bump him up to the Triple-A ranks. Shuster will turn 24 in early August, so there's a chance this is not his final promotion of the season.