Manager Buck Showalter had indicated that the team might need to call up a right-handed long reliever for the Tigers series, which begins Monday, because of Detroit's righty-leaning lineup and the need to use McFarland for three-plus innings Sunday.
"We'll see. We'll talk about it," Showalter said after the game. "We'd like to make sure we have some length there. Detroit's primarily right-handed."
Steve Johnson is also an option, as he hasn't pitched since Thursday.
McFarland, 24, heads back to the minors after posting a 3.86 ERA in three appearances for the Orioles.