The Red Sox announced the move before Friday night's 8-5 win against the Cleveland Indians.
Manager Alex Cora said earlier Friday that Duran wasn't feeling well and would not be with the team as he underwent testing. The club announced a few hours later that Duran had been added to the list, which has been growing since Boston placed infielders Enrique Hernandez and Christian Arroyo on it Aug. 27.
Cora said Hernandez has been feeling better but was unlikely to return to the lineup this weekend. Arroyo could be back by the middle of next week and shortstop Xander Bogaerts, who was pulled from a game Tuesday and added to the list, might return by the end of next week, Cora said.