Astros' starter Roy Oswalt has had his next scheduled start pushed back once again because of an ailing left hip, according to The Houston Chronicle. He was supposed to start on Tuesday but will be replaced in the rotation by Brandon Backe. Oswalt will throw off flat ground Monday and throw a bullpen session Tuesday before being re-evaluated. Oswalt was originally supposed to start Saturday but was pushed back to Tuesday to give the team more time to evaluate him. "He said originally the abductor muscle was hurting him when he rotated out, but this was a little bit higher," GM Ed Wade said. "Because it was an issue that seemed to be in a different position, it made sense to get him back."