On April 25, 2018, the Braves promoted Acuña to the major leagues.[20] This made him the youngest player in Major League Baseball at that time,[21] claiming the distinction from teammate Ozzie Albies.Though Acuña wore uniform number 24 throughout his minor league career in honor of Miguel Cabrera, he made his major league debut on April 25, 2018, wearing number 13. Acuña collected his first career hit off Kevin Shackelford. He finished the game 1-for-5 and scored the game-tying run in the eighth inning as the Braves won 5–4 The next day, also against the Reds, Acuña hit his first MLB home run off Homer Bailey. He finished the game 3-for-4 as the Braves won 7–4. This bat was used at the very start of his rookie season.