Matt Cain (hamstring) will not start on Saturday in St. Louis. Cain's recovery from a strained right hamstring is coming along fine, as he threw Wednesday and Thursday with no issues. However, the Giants just want to be safe. Yusmeiro Petit will fill in for Cain again on Saturday. Cain will be placed on the disabled list but is expected to start on June 6, the first day he's eligible to return.