MINNEAPOLIS -- After Billy Butler was thrown out at second base Friday night trying to advance on a throw, the Royals revised their verbal signals.

"He thought he heard, 'Go, go, go,' and it was, 'No, no, no,'" manager Trey Hillman said.

The problem is the noise in the Metrodome is amplified, and it's difficult for baserunners to hear over the crowd racket.

"It was my fault," said first-base coach Rusty Kuntz. "It's OK when you're outside, but not in the dome."

Kuntz is revising his instructions to "Right here" or "Stay here" or the old reliable "Stop!"

"I thought he said, 'Go, go, go,' " Butler said. "It's close. It's just hard to hear."