Kubiak said Walter bruised his left collarbone and will be re-evaluated "in a couple of days."
"He does not have a fracture," Kubiak said, according to the Texans' official website, refuting reports that the receiver had suffered the more serious injury. "It's being treated as a bad bruise right now, and we should know more here in a couple days. ...
"We'll see where he's at middle of the week, end of the week, but he does not have a fracture, so that's good news."
Kubiak said Foster worked out his left hamstring Monday and might practice Wednesday. Houston plays Sunday at Miami.
The Associated Press contributed to this report.