Brett Wallace has been facing fewer lefthanded pitchers all year to the point where he's been pinch-hit for recently in the late innings with lefties on the mound, and now there appears to be more of a drop in Wallace's playing time.

The first baseman was out of the lineup against Cardinals righthander Kyle McClellan on Monday and will be used less frequently as manager Brad Mills tries to get him more favorable matchups in the near future.

"We're going to pick a few matchups and try to get him going and get him in gear to hit like he's capable of hitting," Mills said.

Wallace, 24, has been at the center of a tug-of-war between the Astros' desire to win every game possible and develop him for the future as he has struggled against lefties.

But Mills on Monday took a somewhat longer-term view.