The Pirates optioned Kelly to Triple-A Indianapolis on Saturday, Danny Demilio of PittsburghBaseballNow.com reports.
Kelly will head back to the minors after giving up two earned runs in 2.1 innings during his MLB debut Friday. The 22-year-old owns a 4.50 ERA and 1.48 WHIP through 54 frames at Indianapolis while working primarily as a starter and could be called upon to make additional appearances for the Pirates later in the season -- likely as a long reliever. Isaac Mattson was recalled from Triple-A to fill the open spot in Pittsburgh's bullpen.