"I've been feeling great, pitching good. This came out of nowhere," O'Day said. "I wish I knew, try to figure it out. This is something I've had to deal with. I've had a torn labrum since 2009, so it's happened a few times in my career. It's just part of it. It's not natural to throw as much as we do. We'll try to figure it out and try to stay on top of it."