Casilla has been hitting well recently, as he entered Tuesday's game hitting .300 with a .323 on-base percentage in 19 games. He also has a team-high five stolen bases.
"Casilla is swinging very hot," Twins manager Ron Gardenhire said. "He's running the bases aggressively. So I just flip-flopped them. I had Casilla there for a long time. So I thought I'd try it out and put Carroll down there."
Carroll has struggled with a .214 average, but has still has posted a .320 on-base percentage on the strength of 12 walks.
"I think Jamey has been doing a great job," Gardenhire said. "His batting average is not great right now, but his on-base percentage is still .320 or something. So that's pretty good for a second hitter and I have no doubt he can handle that. But Alexi is swinging it pretty good. And I want to get some people on in front of those guys out there."