Afterward, Yost searched for something positive to say but came up empty.
"He just labored from the first inning on," Yost said. "I thought his last start was better than his first start. But I thought he labored [tonight]."
The Royals even staked Cahill to a 3-0 lead. That lead was gone by the third inning.
"I didn't even make it through the third, which is embarrassing," Cahill said.
In three starts since the trade, Cahill has yet to make it through the fifth inning. With the Royals, he has given up 10 runs in 11 innings while walking nine and has an 8.18 ERA.
The culprit, Cahill said, is his inability to command his sinker or his out pitch, his curveball.
"Last four starts, I've been battling command," Cahill said. "Sinker hasn't been there and curveball hasn't been there. The curveball is not even close. I'm left trying to get through with just changeups."
And the Royals are left looking for solutions as they now have lost eight of 10 and remained four games out of first in the American League Central.
One internal solution could be right-hander Jakob Junis, who pitched well Sunday, giving up one run and four hits over eight innings. Or the Royals could still deal for another arm that has cleared waivers.
Whatever it is, Yost knows the sense of urgency is there.
"Offense was really good (tonight)," Yost said. "We jumped out early. Offense did a great job. We need to pitch better."
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.