Mariano Rivera turned 43 this past November. He began his 19th major-league season on Wednesday morning, beneath a gunmetal gray sky that eventually parted for the sun. He has five World Series rings. He’s made 12 All-Star games. He’s finished in the top three in Cy Young voting four times. He owns a 0.70 ERA in 141 playoff innings, and has given up one October run since 2005. Whenever he opts to retire, after the five-year waiting period, he figures to cruise into Cooperstown. So why is he here? What motivates him to continue his career, even after ACL surgery last May? “The love of the game, for one thing,” he said. “The passion that I have for this drives me. I come here to win. Regardless. This is the beginning. This is the preparation for that. So when I come here, my mind is already going to a different level. And that is winning championships. It doesn’t start in October. It starts in February, for me. That’s the way I think. And that’s what motivates me.” Did Rivera ever doubt he could return from ACL surgery? “I don’t think that way,” he said. “I’m a positive man. So I always think positive. There were many times when I had, not doubt, but soreness. Pain, I would say. But it never went through my mind that I didn’t want to do it again. I was up to it. It was a challenge for me. And something like this, it’s not easy. You just have to work at it, and find a way to get it done.”