McFarland was placed on the injured list without a designation Wednesday.
Since the Cardinals didn't provide a reason for placing McFarland on the injured list, he's likely on the COVID-19 IL. Assuming that's the case, the southpaw will be eligible to rejoin the team as soon as he clears the league's health and safety protocols. His return timetable depends on whether he's tested positive for COVID-19, but right-hander Junior Fernandez was recalled to take his place in the bullpen.