A first-round selection by the Astros in 2010, "Folty" debuted with the parent club in 2014, tossing 16 games in relief. The hard-throwing righthander was dealt that offseason to Atlanta for Evan Gattis and James Hoyt.

Foltynewicz made the NL All-Star team in 2018. Overall, through 2019, he has posted a 44-41 record with a 4.27 ERA.