Juan Nicasio will undergo surgery on July 16 to remove a "floating body" from his left knee. Nicasio originally landed on the disabled list in early June with a left knee strain. He has had the knee drained twice already, most recently on Wednesday night. The timeline on his return will depend on whether additional damage is found during surgery. It's a tough blow for the 25-year-old right-hander, who bounced back from a broken neck last August and made the Rockies' starting rotation out of spring training.