Butler played only long enough to bat once in Wednesday's 6-3 win over the Los Angeles Angels, but he drilled a double down the left-field line. That raised his Cactus League average to .419 (13-for-31). He has two doubles, two home runs and seven RBIs.
This came just a day after he'd rocked a solo home run and a two-run single off Arizona ace Dan Haren.
On Wednesday, Butler said he likes to go against the big guns like Haren.
"When you read [a name] on the lineup like that, or Barry Zito, guys that have big names, I think, in a certain aspect, you lock in more," Butler said.
"I know I've got to be ready for this guy because he's got some quality stuff. I faced him quite a bit last year [with the A's] and the second time this spring, so I felt comfortable yesterday. Hopefully, that stays the same. That guy can change the next time I face him, that's why he's so good."
The Diamondbacks are one of the Royals' Interleague rivals this season.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.