Atlanta selected Kerr's contract from Triple-A Gwinnett on Sunday.
In a corresponding move, Danny Young was designated for assignment to open up room in the big-league bullpen for another lefty in Kerr, who last appeared in the majors with Atlanta in 2024. In that season, Kerr submitted a 5.64 ERA and 1.61 WHIP across 22.1 innings before undergoing Tommy John surgery that June. Kerr didn't pitch at all in 2025 and got off to a delayed start to 2026 while completing his recovery process, but he's looked good since returning to game action in the minors in mid-July. Over nine appearances across stops with four different affiliates, Kerr has posted a 16:5 K:BB while holding opposing hitters to a .171 average over 11.1 innings.