On September 18, 2025, Abner was selected to the 40-man roster and promoted to the major leagues for the first time.[4] He would make his debut the following day against the Philadelphia Phillies, pitching for 2⁄3 innings while letting up one hit and striking out both Kyle Schwarber and Brandon Marsh.[5] Abner made five appearances for the Diamondbacks during his rookie campaign, recording a 4.91 ERA with five strikeouts across 3+2⁄3 innings pitched.
Abner was optioned to Triple-A Reno to begin the 2026 season.[6]