Right-hander Shawn Chacon will start on Tuesday against Nationals right-hander Shawn Hill at Minute Maid Park. Roy Oswalt will go on Wednesday opposite Nationals lefty Odalis Perez, while right-hander Brandon Backe, who picked up the victory on Saturday night against the Brewers, will go on Thursday vs. southpaw John Lannan in the final game of the homestand.
"We've got [to be determined] after that," Cooper said. "Maybe [Chris] Sampson, could be Brian Moehler. Could be somebody else. Just depends, and it could be Sampson if we try to keep him on his normal [rest]."
Sampson started Sunday against Ben Sheets and the Brewers, so his turn would come up again on Friday. The Astros could also make a roster move. Rodriguez will be re-evaluated again on Monday after he makes his scheduled throwing session.
"We'll probably determine it by Tuesday, I would think," Cooper said.
Jim Molony is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.