Choo will bat leadoff in every inning and play the outfield.
"The plan is to start with three days and then we'll make a decision," Rangers manager Jeff Banister said. "It's probably a little more accelerated situation. We don't have a lot of time. He is going to have to get as many at-bats as he can."
Choo is one reason Banister said setting the postseason roster will be "extremely challenging." The Rangers still have decisions to make on reliever Tony Barnette, who has been sidelined for three weeks with a strained muscle in his left side, and Jeremy Jeffress, who hasn't pitched in a game since Aug.