Hartman was designated for assignment by the Orioles on Wednesday.
Hartman was claimed off waivers by the Orioles at the end of July and spent time on the COVID-19 injured list while he underwent intake testing. He made two appearances (one start) at Triple-A Norfolk and gave up four runs on five hits and two walks while striking out one in 2.1 innings. He'll now be cast off the 40-man roster after Zack Burdi was claimed off waivers by the Orioles on Wednesday.