Then Alex Gordon was hurt, Teahen moved over to third base and Callaspo was put at second base. Now Callaspo is the Royals' hottest hitter.
Going into Tuesday night's game against Toronto, Callaspo had a 10-game hitting streak (16-for-36, .444) and his average was .386, ranking third in the American League behind Boston's Kevin Youkilis (.414), and Cleveland's Victor Martinez (.390).
Callaspo also had hit in 15 of the 17 games in which he'd played this season before going hitless Tuesday.
"I don't count how many games," Callaspo said. "I try to hit the ball good and do my job."
He's done that well, even connecting for his first Major League homer on Friday night against Detroit's rookie whiz, Rick Porcello. He'd gone longer, 441 at-bats, than any active big leaguer without one.
Callaspo has a great knack of making contact. In his first 57 at-bats, he'd struck out just three times. Last season, he fanned just 14 times in 213 at-bats.
The result of hard work or just a natural talent?
"Everybody has to work hard," Callaspo said. "That's what I do, and maybe it's natural, too. I just see the ball and swing. I just try to make contact and see what happens."
Callaspo began switch-hitting when he was a kid in Maracay, Venezuela.
"I started when I was like 10 years [old], and it seemed natural to me," he said. "It's working right now."
"He's impressive because he doesn't try to do too much at all, he just continues to put the barrel on the ball," Teahen said. "It's amazing to see the type of pitchers he can do that with, whether it was [Joel] Zumaya the other night throwing 99 mph or [Vicente] Padilla throwing a slow curveball, he seems to be able to put the barrel on anything. It's fun to watch."
Callaspo was obtained from the Arizona Diamondbacks prior to last season in a trade for pitcher Billy Buckner. He got into the battle for second base with Teahen and Willie Bloomquist by virtue of batting .319 after coming off the disabled list on Aug. 23 last season.
For him, a 10-game hitting streak is just a bunt. He hit in 18 straight games last Sept. 7-27.
Gordon, after hip surgery, is expected to be out until at least late June.
"We'll see how it plays when Gordon gets back," Teahen said, "but for now, it's nice that I can slide over to third and do a job and Alberto can play a good second base. And hitting like he is, it's incredible," he said.
And Callaspo was supposed to be spending most of his time on the bench.
"I finally got my chance and I try to do my job, and that's it," he said.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.