Both Royals manager Ned Yost and Cueto insist there is nothing physically wrong with the veteran hurler.
"If there was something wrong, our trainers would know," Yost said. "They have all these tests, and if there is an injury somewhere, you'd be weak in that area. He's checked out OK."
Cueto gave up four home runs and seven earned runs in 6 1/3 innings Sunday.
"He lobbied to pitch the seventh," Yost said. "That's not what a guy who's hurt says. I can't jump in his body and see how he feels. I can only go by what he says."
Cueto said through interpreter Pedro Grifol: "I feel like I've felt every time. I feel strong, healthy."
So the question becomes: What's the solution?
Yost said he doesn't want Cueto to skip a turn in the rotation.
"They've had some success in the past skipping him a start, but that's been because of injury problems," Yost said. "He feels good right now. So it really doesn't make sense."
Cueto also doesn't want to skip a start.
"I'm not going to say [I want to]," he said. "I'm Johnny Cueto. I'm healthy. I need to take the ball every five days."
Yost believes that the issue is with Cueto's approach to hitters right now.
"What he needs to do is establish his fastball more," Yost said. "And when he does that, it will open up things for his secondary stuff.
"He gave up the home run on the fastball to Adam Jones tonight, but everything else [that was hit] was on cutters and changeups."
Cueto, however, isn't buying that explanation.
"When things go bad like this, everyone looks at all the negatives, like, 'He could have done this or done that,'" Cueto said. "What needs to happen is I need to keep fighting. This is going to change. In the end, I'm going to do what I came here to do."
Cueto says he feels no added pressure trying to be an ace for the defending American League champions.
"This is baseball. It's not added pressure," he said. "I'm going to continue to work hard. When the bell rings for the playoffs, I'm going to be there for this club."
But is Yost considering altering his playoff rotation?
"Not right now," Yost said. "But it may if this continues. But frankly, I don't see it continuing."