Mathis (Achilles) hasn't received clearance to take part in on-field work when training camp opens Sunday, the Indianapolis Star reports. "The good news is Robert is trending in the right direction," owner Jim Irsay said. "We're all very excited and pleased with the progress that he's making. The timetable is unknown. Will it be Oct. 15? Will it be Sept. 15? I really, at this point, no one knows."