Martin was with relatives, and his issues didn't involve any problems with the coaching staff, the person said. The person spoke to The Associated Press on condition of anonymity because the Dolphins have said not released any details of the illness.
Martin, 24, played in Sunday's loss at New England, then missed practice this week. He was replaced by Tyson Clabo, who started Miami's first six games before being benched.
A second-round draft pick from Stanford, Martin started every game at right tackle as a rookie last year. He switched to left tackle this season, then moved back to the right side last week in a reshuffling of the Dolphins' struggling offensive line.
"You can approach this two different ways," Martin said last week regarding his latest position switch. "You can go in the tank and be one of those guys that moans and is a cancer in the locker room, or you can be a professional and play as hard as you can. My mindset is I'm going to go out there and do whatever I can to help the team win."
Pass protection has been a problem for Miami all season. Ryan Tannehill went into the Bengals game with an NFL-high 32 sacks, and the Dolphins (3-4) were saddled with a four-game losing streak.
Martin's agent didn't respond to requests for comment.
In an unrelated move, the Dolphins promoted receiver Ryan Spadola from the practice squad to the active roster.
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