Ryan Mathews had an impressive debut in his first NFL preseason game. Mathews tried to keep his mind off his unofficial debut all day, then vomited in the locker room shortly before the game. ?Nerves,? he said afterward. Mathews ran nine times for 50 yards and caught one pass at the line of scrimmage, bowling through one tackle for a 7-yard gain. ?It was crazy at first,? Mathews said. ?My adrenaline was going.?