Jeremy Affeldt has landed on the disabled list with a non-baseball injury for the second time in less than eight months. The left-hander sprained his right knee on Saturday night when he reached out to catch his four-year-old son as the 60-pound boy jumped off the couch to hug his father. Affeldt said he heard a pop but didn't think there was anything seriously wrong. However, he woke up at 4 a.m. Sunday with throbbing pain. An MRI exam revealed the sprain for Affeldt, who last Sept. 8 sliced his non-throwing hand nearly to the artery while separating frozen hamburgers. "There was some light swelling but there wasn't a lot, so I knew it probably wasn't a huge deal or a major tear," Affeldt said. "But it was enough pain that I didn't think I could get off the mound if I had to."