Scott Sizemore is scheduled to return to Oakland on Wednesday to undergo an MRI on his left knee. Sizemore left Tuesday's game against the Angels due to a sprained knee. The 27-year-old underwent surgery on the very same knee last spring, so he's hoping it's just scar tissue. However, the banged-up Athletics will likely be forced to make a roster move. Andy Parrino is the leading candidate to be called up from Triple-A Sacramento.