By Zach Koons Chicago’s ace left his Opening Day start early after he felt discomfort in the injured area. The White Sox will be down a second member of their rotation as starting pitcher Lucas Giolito is headed to the 10-day IL with an abdominal injury, manager Tony La Russa said Saturday. Giolito is expected to miss his next two starts, per La Russa, after leaving his Opening Day outing with what was described as “abdominal tightness” on Thursday. He still managed to strike out six batters and give up just one hit in four innings of work, but alerted the training staff when he felt lingering…