Left-hander Ryan Feierabend got the start Sunday instead. He had been scheduled to pitch on Wednesday.
Silva said he has sharp pain in his upper back. The right-hander first felt the ache on Saturday during a workout. He came in Sunday morning and told team trainers and manager Jim Riggleman he could not start.
Silva is 4-14 with a 6.53 ERA in his first season after signing a $48 million, four-year contract with Seattle. He returned last Monday from two weeks on the disabled list with tendinitis in his pitching elbow.