Updated

The Boston Red Sox have placed right-handed pitcher Clay Buchholz on the 15-day disabled list Sunday due to what manager Bobby Valentine called a "gastrointestinal issue."

Valentine said Buchholz had gone to the hospital recently to deal with the problem and has not been with the team the past two days.

Boston is planning to activate Aaron Cook from the 15-day DL to start Sunday against the Braves.

Cook was placed on the 15-day disabled list on May 6 after suffering a left knee laceration when he was spiked covering home plate.