Curtis was promoted to Triple-A Indianapolis on Sunday, Anthony Murphy of DKPittsburghSports.com reports.
Curtis will make the leap to the Triple-A level after posting a 4.73 ERA and 1.28 WHIP with 67 strikeouts over 53.1 innings in 12 starts with Double-A Altoona this season. The right-hander is considered to be one of the Pirates' top overall prospects, and he is now just one step away from making his major-league debut.