Porter looking to establish regular lineup

DENVER -- The Astros' lineup will likely remain a work in progress as long as they remain knee-deep in their rebuilding process, though some spots have slowly worked themselves out. The Astros used 45 batting orders in their first 52 games.

With outfielder Robbie Grossman in Triple-A Oklahoma City, Brandon Barnes is getting more of the playing time in center while leading off. Manager Bo Porter likes Jose Altuve in the No. 2 hole, Jason Castro at No. 3 and lately J.D. Martinez in the clean-up spot.

The fifth and sixth spots alternate between Carlos Pena and Chris Carter. Porter also likes Matt Dominguez in the eighth spot, though he was hitting seventh in a National League ballpark Wednesday so veteran Ronny Cedeno could hit eighth in front of the pitcher.

"I try to do everything I can to put guys in positions I believe they are going to be successful," Porter said. "I want to have continuity as much as we can, but at the same time, when roster moves are made or changes are made, you have to adjust to those changes being made."

Porter said established teams like Detroit, which has Torii Hunter hitting second, Miguel Cabrera third, Prince Fielder fourth and Victor Martinez fifth almost each night, have a luxury the Astros don't have at this point.

"They run the same guys out there every day," he said. "Our guys have not established themselves to that point, and that's what we're working through."

Brian McTaggart is a reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.