But as dismal as the loss was, the first impression of Cueto was a sound one.
"He pitched really well," Royals manager Ned Yost said.
Added center fielder
Lorenzo Cain: "He pitched well. He had the lead and unfortunately we weren't able to get him a win. It's a tough loss, but we'll bounce back."
Cueto gave up three runs on seven hits, walking two and striking out seven.
"I think I threw the ball pretty good," Cueto said through interpreter Pedro Grifol. "I felt good overall and felt good on the mound. I made one bad pitch and the rest of the game went good."
Cueto on his Royals debut
KC@TOR: Cueto discusses first start with the Royals
7/31/15: Johnny Cueto breaks down his first start with the Royals and his ability to execute pitches against a tough Blue Jays lineup
The mistake was a hanging changeup to the red-hot
Josh Donaldson, who drilled a two-run double in the third.
"I tried to get that down and I made a mistake," Cueto said. "You got to execute every pitch. You make a mistake and you'll get hurt."
Cueto also seemed at times to have trouble getting in a rhythm with catcher
"Obviously he's a very good catcher," Cueto said. "I just have to continue to work with him and that will come with time."
is a reporter for MLB.com. Follow him on Twitter at Jeffrey Flanagan . This story was not subject to the approval of Major League Baseball or its clubs. @FlannyMLB