Clay Buchholz has inflammation in the bursa sac of his right shoulder, but other than that an MRI revealed no structural problems with the shoulder or any issues with his sore trapezius muscle near the base of his neck. He will be shut down for at least the next two days before being allowed to throw a baseball again. At this point, it appears unlikely Buchholz will be able to pitch before the All-Star break next month, but it is too soon to make that call. “I’m going to take a couple of days off throwing,” said Buchholz, who was upbeat during a short exchange yesterday. “Once the inflammation goes down, I can throw again.” The bursa sac is located underneath the AC joint, or the end of the collarbone that sits above the shoulder joint. The inflammation could have been responsible for the irritation in the AC joint that bothered Buchholz earlier this month. If it is related to the sore neck muscle is unknown. Buchholz said the MRI was the first he has had on his shoulder since signing an extension with the Red Sox in April 2011. Aside from the bursa sac inflammation, the MRI’s were “identical,” said Buchholz.