"But will he be part of the rotation again down the road?" Yost said. "I would have to say yes."
Young has been recovering from a right forearm strain.
Flynn was 1-0 with a 4.91 ERA in five relief appearances. However, Yost said Flynn would go to Omaha to transition to a starting role.
"We're just a little thin in terms of starters there," Yost said. "So we're going to stretch him out. It's a need right now."
Jeffrey Flanagan has covered the Royals since 1991, and for MLB.com since 2015. Follow him on Twitter @FlannyMLB. This story was not subject to the approval of Major League Baseball or its clubs.