Dunning is expected to work out of the bullpen for Atlanta, Mark Bowman of MLB.com reports.
While the team is in need of starting pitching depth, Dunning will instead fill a long-relief role once he joins the big-league roster, providing length behind what will likely be a parade of unproven or unreliable arms in the rotation during the second half of the season. The 30-year-old right-hander has made five MLB appearances for the Rangers in 2025, all in relief, and posted a 3.38 ERA, 1.31 WHIP and 10:5 K:BB over 10.2 innings.