Padres manager Jayce Tingler confirmed Monday that Guerra (elbow) would begin the season on the injured list, Kevin Acee of The San Diego Union-Tribune reports.
Guerra is one of seven relievers set to open the season on the shelf for a banged-up Padres pitching staff. The 25-year-old righty didn't pitch during the Cactus League slate while recovering from a Grade 1 UCL sprain, so he'll likely be in line to spend more than the minimum 10 days on the IL.