"What?" Swisher said to reporters. "You've never heard of 'Costume Monday?'"
There was more to this wild day in Goodyear than simply a bring-your-own-costume team event. The players were piecing together their own version of the "Harlem Shake" craze that caught fire last month and recently hit highlight shows when the NBA's Miami Heat posted its own version of the YouTube sensation.
The Indians' video will likely hit the Internet within the next week.
Cleveland pitcher Brett Myers dressed as a wrestler -- complete with a title belt. Pitcher Josh Tomlin donned a "Naked Cowboy" costume similar to the famous Times Square performer in New York City. Lefty Rich Hill was dressed as the Easter Bunny, and 42-year-old veteran Jason Giambi wore a green skin-tight suit that covered his entire body.
"It was fun," Giambi said. "That's the stuff you need to build team unity."
Even Indians manager Terry Francona got into the act by putting on a baby costume, which included a bonnet.
"Hey, whatever helps the team win," Indians starter Justin Masterson said. "That's what he's all about."
Francona's outfit was hand-picked by bullpen coach Kevin Cash.
"He gave me a couple choices," said Francona, rolling his eyes. "He had a bunny rabbit, but I couldn't get into it. The guys had fun with it. It was Swish's idea, which I don't think is a shock to anybody. It was all in good fun, and everybody did it. You've got to laugh at yourself a little bit."
Swisher said that was partially the point of the day's antics.
"You've got to have fun in this game, man," Swisher said. "We're kind of in the grind of spring right now. So I figured a little costume Monday would really spice it up -- take away the monotony. Man, the boys came through full force. We had so much fun this morning."
Jordan Bastian is a reporter for MLB.com. Read his blog, Major League Bastian, and follow him on Twitter @MLBastian. This story was not subject to the approval of Major League Baseball or its clubs.