PEORIA, Ariz. -- Rene Rivera's outlook on life has changed dramatically since the end of last season. Becoming a father for the first time will do that to a man.

Rivera and his wife, Mariel, welcomed twin girls to the world last fall, Ivanna and Julianna. Now everything the Padres' journeyman catcher does, he says he does for them and their futures.

"When you have kids, it's no longer about you. It's about them," Rivera said. "The girls are the light of my life. They are a blessing and the best thing that's ever happened to me."

Fatherhood can be a scary thing. In the past, Rivera's success and failures for the most part only impacted himself. But with two children depending on him, that isn't the case anymore. That's why this offseason, Rivera dropped 25 pounds in an effort to become more agile behind the plate and enhance his chances at sticking with a big league team.

"Being a father makes you work harder because you want to take care of them," he said. "You want to perform well to make them proud. You want to stay a while longer in the big leagues to make more money for them when they grow up."

At 30, Rivera is still relatively young in the traditional sense of the word. But with 13 seasons of professional ball under his belt, he certainly has a lot of miles on him.

He began his career at 17, coming to America from Puerto Rico as the Mariners' second-round pick in 2001. The backstop moved rapidly through the Minors thanks to his defensive prowess, and not long after his 20th birthday, he made his Major League debut in 2004.

That, however, is where Rivera's ascension stalled. Although his glove and arm remained a strength, those aspects of his game weren't enough to keep him in the big leagues as he hit just .206 in 150 at-bats over parts of the next three seasons with the Mariners.

For the next four years, Rivera bounced around in the Minors and even found himself in the Independent League at one point. He eventually returned to the big leagues in 2011 with the Twins, but that stint proved to be short-lived as well as he hit just .144 in 45 games before returning to the Minors. Still, Rivera marched on and the Padres became his sixth organization following the 2012 season when the club took a flyer on him to provide depth at catcher in the farm system.

"When you take a young player and he gets an opportunity to play professional baseball, you'll find in the vast majority of cases, it's tough to take the uniform off him," Padres manager Bud Black said. "In Rene's case, he's a guy with talent, he has the skill to catch and throw at the Major League level, but he just hadn't been able to consistently to put together spurts to make those clubs sustain his Major League service."

With San Diego, Rivera finally came into his own in 2013, turning in the best and most complete season of his career. Not only did he throw out 46 percent of base stealers for Triple-A Tucson, he also flourished at the plate, batting .343 with 23 extra-base hits in 74 games. The Padres rewarded him with a callup when Yasmani Grandal suffered a season-ending injury in July and Rivera went on to appear in 23 big league games, hitting .254 and gunning down nine of 16 base stealers.

As for how Rivera was able to turn his fortunes around, the catcher credits the success to getting older. He believes he's now at the point of his raw talent converging with the wisdom that comes with age.

"This is the peak of my career," Rivera said. "This is the best I've ever been. It's been a long process with a lot of bumps in the road, but it's led me to here."

Added Black, "I think last year with us maybe a couple things clicked. Where he is age wise, he's realizing that perspective and knows what he has to do to be the best player he can be. That's finally coming to fruition for him. We were impressed with his skill set last year, so we'll see where he goes now."

In just the two weeks since camp began this spring, Rivera can already feel the difference his weight loss has made. He's moving better, he has more stamina and he's generally more confident in his abilities.

With Grandal's readiness for the start of the season in limbo, Rivera is expected to make the 25-man roster as the backup catcher to Nick Hundley, a feat that would be a career first for the veteran.

What a year that would be, become a father in the fall, make an Opening Day roster in the spring.

"I can't describe how much it would mean to me to make the team," Rivera said. "It's another goal I want to achieve, so I'm working hard to accomplish it."