Orioles second baseman Brian Roberts will undergo an MRI Friday on his right shoulder after missing the last two games with a strained rotator cuff, The Baltimore Sun reported on Thursday. Baltimore is already without Javy Lopez (broken right hand), Larry Bigbie (left hamstring), Luis Matos (broken right ring finger) and Erik Bedard (left knee MCL), all of whom are currently on the disabled list. According to The Sun, Roberts left the team before Thursday's game against the Red Sox and will be examined by orthopedist Dr. Charles Silberstein in Baltimore. "I don't think it's any better," Mazzilli told MLB.com. "We want to have the doctor check it out and see where we're at. I would say, in all probability, he won't be playing this weekend, but we'll see what the doc says [Friday]."