The person said Thursday that Martin was with relatives, and that his issues didn't involve any problems with the coaching staff. The person spoke to The Associated Press on condition of anonymity because the Dolphins have not announced any details of Martin's illness.
Martin, a second-year pro, played in Sunday's game at New England, then missed practice this week and was expected to sit out Thursday night's game against Cincinnati. He will be replaced by Tyson Clabo, who started Miami's first six games before being benched.
Martin's agent didn't respond to requests for comment.
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