Defensive back Tyrann Mathieu's rehabilitation from knee surgery is proceeding on schedule, but it remains doubtful that he will be ready for the start of training camp this summer. "I think Ty is going to up to the wire," coach Bruce Arians said this morning before the team's charity golf event. "I still anticipate him on PUP, but he refuses to believe it. That's a good thing." Asked about Arians' comments about PUP, Mathieu responded with a question. "What's that?" "Physically unable to perform," he was told. Mathieu smiled for a few seconds, suggesting he's not planning on missing practices.