Except for a home run in Wednesday night's 5-3 loss, Perez had been in a batting funk, going 1-for-25 in his last six games. After his booming blast to center, he struck out in his last three times at bat -- and Perez seldom strikes out.
"He's just struggling offensively, he doesn't need it physically," manager Ned Yost said.
Previously, Hayes had been in just two games with one at-bat.
"I didn't want to do it, but Hayes hasn't played in a while and I really didn't want to put him in the six-hole," Yost said. "So the best way is just move everybody up and keep the right-left balance except for the first two hitters, who handle lefties pretty well anyway."
Omar Infante was taken out of his customary second spot behind leadoff man Nori Aoki and inserted into the fifth spot with Eric Hosmer, Billy Butler and Alex Gordon moving up to 2-3-4.
"Omar is really tough with runners on," Yost said, aware that Infante's 10 RBIs were second only to 11 by Gordon and Mike Moustakas.
Moustakas, Alcides Escobar and Jarrod Dyson each moved up one spot in the order as Hayes settled into the No. 9 position.
Going into Thursday's games, only 1 1/2 games separated the five teams in the American League Central standings.
"This is the toughest division in the American League in terms of weather. It's the coldest -- we've got Minnesota, Cleveland, Detroit, Chicago. They're all cold-weather cities. Early in the year, it's tough for your offense to get going," Yost said. "You look at our division, we're all scrambling. Nobody's running away, everybody's doing the same thing. Once it warms up, it'll get a little better."
Of the five division teams, the White Sox and Twins were doing well in run production, standing first and third respectively in the 15-team AL. But the Indians were eighth, the Tigers 13th and the Royals 14th.
However, Indians pitcher Justin Masterson, who gave up back-to-back homers to Perez and Moustakas, expressed respect for the Royals' potential.
"They've put together some really good young talent, some guys that take some big hacks and can hit it far. I mean back-to-back homers off of me. You make a few mistakes, they make you pay for it," Masterson said.
"They made it tough last year and it's going to be tough again this year. That's kind of the way you see it in the Central. Everybody plays each other really tough, some good young talent. We're all going to make some mistakes as we go about it, but I think whoever limits their mistakes the most is going to be on top."