After previous X-rays confirmed that Chicago Cubs pitcher Mark Prior did not break a bone in his left elbow, a subsequent MRI revealed a hairline fracture that will have him on the disabled list for two months or more. Cubs trainer Mark O?Neal has said the decision on when to allow Prior back will be a difficult one. "That's a tough question, [one] everybody's going to be asking," he said. "It's really going to be determined by how sore he is, how much inflammation. If you've ever been hit by anything, you swell within the first 24 hours. We're going to have to wait and see how he is [Saturday]. "There's no way we can tell right now how long this is going to be."