Mariano Rivera tore the ACL in his right knee while shagging balls during batting practice in Kansas City on Thursday night. The 42-year-old right-hander's leg got caught on the field where the grass meets the dirt, causing his knee to buckle. He had to be carted off the field. "I thought it wasn't that bad, but it's torn," Rivera said after the game, pausing several times to compose himself. "Have to fix it." Rivera said that he never gave a thought to getting hurt while chasing balls during batting practice. It's something that he's done his entire career to keep in shape. "At this point, I don't know," Rivera said when asked if he thought his career might be over. "At this point, I don't know. Going to have to face this first. It all depends on how the rehab is going to happen, and from there, we'll see."