"Something new, something different," said Madrigal, known as the "Mad Dog" in the clubhouse.
"Now he really looks like a dog ... a bulldog," manager Ron Washington said. "He's trying to change things."
Madrigal made his first appearance of the season on Friday against the Tigers. He retired the first five hitters he faced, then hit Gerald Laird with a pitch. Suddenly everything changed and he walked the next three hitters.
"I don't know what happened," Madrigal said. "Everything happened so quickly. When I thought about it after the game, I just thought that I lost my focus and concentration."
Madrigal usually throws strikes. That was only the second time in 32 Major League relief appearances that he's walked three batters in an outing. He's only walked two in an outing three other times and averaged 3.50 walks per nine innings as a rookie last year.
Madrigal ended up allowing four earned runs, his most since giving up five in his Major League debut on July 2, 2008, at Yankee Stadium.
"I'll be back," Madrigal said. "I'll forget about this one. I forgot about that one, I'll forget about this one."
T.R. Sullivan is a reporter for MLB.com.
This story was not subject to the approval of Major League Baseball or its clubs.