The Dolphins have their reasons for sidelining cornerback Vontae Davis for Sunday's game against the Chiefs. They are saying publicly that it isn't because his hamstring is too injured for him to play. Beyond that, however, Miami is keeping the full explanation private. The situation has created some confusion within the locker room, while also resulting in a separate revelation about a confrontation between Davis and wide receiver Brandon Marshall that occurred this week. Davis had to be restrained after Marshall started "talking (trash) and crossed the line," a source with knowledge of the altercation said. The source would not provide specific details of what set off Davis. "Vontae was about to rip his head off," the source said. The altercation never became physical, and neither player threw any punches.