Mills has been turning to Maxwell to start against left-handers in recent days and had him batting third in the lineup against Cubs lefty Travis Wood. Maxwell has hit lefties better in his career (.240 vs. lefties, .174 vs. righties in nearly identical plate appearances), including a .364 batting average this season.
"We're kind of learning as we're going through things, and I don't want to put him in a box because he's got tons of ability and he plays well when he gets the opportunity," Mills said. "You want to give him the best opportunity to have that success."
The Astros claimed Maxwell of waivers from the Yankees on April 8, and he's made 11 starts for Houston. He stroked a go-ahead two-run homer in Saturday's come-from-behind win over the Rangers at Minute Maid Park.
"He definitely has some ability, and I think we've seen it," Mills said. "He can run a little bit, he's put together real well and he's got some strength. We need to get to see him play as we move along. It's probably been an injustice to him throughout his career that he hasn't gotten his opportunity to get 400, 500 at-bats, because that's how you get better."