Jason Hammel said Saturday that he is leaning toward knee surgery, and will likely be placed on the disabled list before Sunday's game. Hammel has a piece of loose cartilage that is hitting a nerve whenever he bends his right knee. If Hammel elects to have the procedure now to remove it, he would likely be out until the beginning of September. Which would further damage the O's chances. Brian Matusz is the candidate most likely to replace him.