The Rangers recalled Dunning from Triple-A Round Rock on Friday.
The right-hander was sent to Round Rock in late August but will rejoin Texas for the final stretch of the regular season. Dunning has started 14 of his 24 appearances in the majors this season but is likely to fill a relief role this time around. He has a 5.38 ERA, 1.43 WHIP and 85:39 K:BB across 90.1 innings.