Dunn was activated from the COVID-19 injured list Wednesday.
He only spent two days on the IL after dealing with an illness. Dunn has a 6.10 ERA and 1.58 WHIP through seven appearances (31 innings), so with Hunter Greene and Graham Ashcraft nearing returns, Dunn could be shifted to a long-relief role before the end of the season. He last pitched Sunday, so he will be available as a starter this weekend in St. Louis.