Fortunately, X-rays came back negative and the productive Boston hitter should be back soon.
"Just a precautionary measure," said Red Sox manager Terry Francona. "He's fine. It was negative. He's going to go and take some swings and see how he feels. Then we'll, after talking to him later, we'll determine, should he pinch-hit, should he go in for defense, should we stay away from him? We'll kind of figure that out."
Because the Mariners have left-hander Erik Bedard on the mound for Wednesday's series finale, Francona would like to get the right-handed-hitting Youkilis back in the lineup. But the manager won't rush him back for that reason. Especially when you consider the Red Sox have an off-day on Thursday.
"When you have Youkilis sitting there, it's hard to fathom playing all your lefties against Bedard," Francona said. "I don't know that we would do that. The nice thing is, if we need to give Youk another day because of the day off, [Sean Casey] swings the bat against both lefties and righties."
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.