MESA, Ariz. -- Barry Zito is falling in love with the game again the same way he did the first time.

His passion for baseball had waned by the time the Giants declined the southpaw's $18 million club option after the 2013 season, his appreciation for the career he had made playing the game lacking. So Zito packed his bags and moved with his wife, Amber, and son, Marsden, back to his hometown of San Diego. He picked up his surfboard and returned to the ocean, enjoyed his new role as a father, and only when he could fully commit himself to dedicating an entire year to baseball again did he renew the process he started more than a decade ago.

"It was nice, just going out to the parks by myself and setting up my net wherever I was and just throw," Zito said Saturday. "Really just get that relationship with the game going again."

Zito rarely went anywhere without that screen and a bucket of balls -- "Kinda like it all started back in the day," he said -- and found it all to be fun again, often throwing to the backdrop of a little league team's practice. He was even reintroduced to the mocking he so often heard from fans in the struggling stages of his Giants tenure.

"There was a Little League kid that came over one day," Zito recalled. "He actually gave me a little attitude. I think he was a Dodgers fan or something. I was like, 'A 10-year-old, you're wearing me out right now?' I thought I got away from this for a second."

But everyone loves a comeback story, and Zito's return to the A's, who selected him in the first round of the 1999 First-Year Player Draft out of USC, has all the makings of a potentially great one. For now, though, the story is still being written.

On Friday, out near the back fields of Hohokam Stadium, Zito was just a non-roster invitee throwing his first bullpen of camp -- albeit in front of a large, curious crowd that included the man who brought him back on a Minor League deal, A's general manager Billy Beane. Zito flashed the smooth, knee-buckling curveball that made him one of the most successful pitchers in the early 2000s, wearing the same No. 75 he did during most of those glory days, and the long locks of hair to pair with it.

Zito still even has that same boyish look to him at age 36. Seemingly not much has changed.

"He's very focused for a guy who's done this a few times," said A's manager Bob Melvin. "And his curveball is still there, that's for sure."

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Zito, who spent his most recent months in Houston working with the same pitching instructor who helped Scott Kazmir reignite his career, is sticking with the basics this time around, ditching the cutter he found himself relying on far too often while with San Francisco.

"The more I threw the cutter, the less feel I had for the curve, the less spin I had on my fastball," he said. "I think the cutter messed a lot of things up.

"I think my delivery just degraded slowly over the years. I'm getting back to fastball, curveball, changeup -- things that really made me who I was that I got away from a little bit."

He's relearning his old mechanics through video of past seasons, particularly 2000-03, when Zito won 61 games, earned an American League Cy Young Award and two All-Star nods while helping the A's to four consecutive postseason appearances.

Much like then, Zito said, "I've conditioned my body, my arm, my mind to be a starter this year, and that's the reason why I've gone back to an arsenal that can get through a lineup three or four times."

Such familiarity is important to Zito, which is why he chose the A's when sorting through his offers this month, despite knowing six other pitchers in camp are also vying for just three open rotation spots.

"I have a fresh perspective, I've got my passion back and I just want to continue to work hard and go out and enjoy competing," he said. "I guess you could say I'm competing against all these guys, but for me, it's more about competing against myself. If I can be as good as I know I can be every time out here, I know the rest will take care of itself."