Mejia, 22, has a 1.94 ERA and 58:16 K:BB in 65 innings for Double-A Richmond.
The 6-foot-3 southpaw is holding opposing batters to a .203 BAA. After only pitching 51.1 innings last season due to a positive PED test and then failing to impress in fall and winter ball, Mejia's stepped up his game this year and is yet another Giants pitching prospect to watch.