Mederos is expected to be recalled from Triple-A Gwinnett ahead of Tuesday's game against the Marlins, Francys Romero of BeisbolFR.com reports.
This promotion isn't official just yet, and Atlanta would need to make a corresponding move to make room on the active roster for Mederos. The 24-year-old, who was traded to Atlanta from the Angels in April in exchange for international bonus pool money, has worked to a 4.81 ERA and 1.48 WHIP with 21 strikeouts across 24.1 innings this season at Triple-A.