He answered "I don't know" and "more backspin," before settling on "I'm definitely stronger."
Manager Ned Yost didn't need to think when asked for his thoughts behind Butler's spike in power.
"He's getting stronger, he's pulling the ball a little bit more," Yost said before Wednesday's series finale with the White Sox. "I've said all along, I think he's capable of being a 30 home runs a year guy."
Yost credited Butler's increased offseason conditioning for him reaching the 20-homer plateau for the second time in his six-year career, the other coming in 2009 (21). Butler hit only 19 and 15 homers the last two years, respectively, but moved this winter to Arizona near the Royals' Spring Training complex in Surprise.
"[He] showed up to Spring Training in the best shape I've ever seen him in and he's maintained it," Yost said.
Butler's increased power hasn't negatively affected the rest of his game. He entered Wednesday batting .301 (.298 career hitter), reaching base at a .370 clip (nine points above his career on-base percentage of .361) and has struck out 70 times (his 162-game average is 93). He also earned his first All-Star nod this season.
That adds to another reason that Butler suspected, and Yost agreed with, about his added power: he's coming into his own.
"He's such a special offensive guy that that's what I expect out of him," Yost said. "I think he's a .300 hitter and a guy that can hit anywhere from 25 to 30 home runs a year, and drive in 100 every year, consistently.
"As an offensive player he can just about do it all. He can drive the ball to all fields. He hits all types of pitching -- there's not a lot of hitters that can hit good pitching like he can."