Yet Cain, who finished 14-8 with a 2.89 ERA last year, is younger than rookies such as first baseman Brett Pill and right-hander Kevin Pucetas, who have never played a day in the Majors. Cain's also younger than right-handers Tim Lincecum, Joe Martinez, Sergio Romo and Brian Wilson, left-hander Jonathan Sanchez, infielders Matt Downs, Kevin Frandsen and Travis Ishikawa and outfielders John Bowker, Nate Schierholtz and Eugenio Velez. But each of them possesses less big league service time than Cain, who turns 26 on Oct. 1.
Go ahead and call Cain a promising young pitcher. He still fits the description. But, having accumulated the longest continuous service time of any current Giant, the club's No. 2 starter also suits the profile of a veteran.
"It seems kind of weird," Cain said Friday of being the senior Giant. "From playing with some of the guys who have been here for so long, like Schmitty [Jason Schmidt] and Richie [Aurilia], it doesn't seem like that's where I am now. It's a cool thing. it's been great. I love being with these guys. I've gone through the system, I came up in the black and orange and I love it."
Thus, when rookie pitchers need advice, they're likely to approach Cain, who just a few years ago was absorbing knowledge and wisdom from the likes of Matt Morris and Dave Roberts.
Example: Shortly after joining the Giants last September, top prospect Madison Bumgarner began following Cain's between-starts training regimen.
"When I got here, I guess he kind of did take me under his wing," Bumgarner said. "He was easy to talk to. ... I feel comfortable asking him about anything. He's just a super-nice guy."
Cain also has the demeanor of an elder who commands respect. Lincecum was only barely joking during his Cy Young news conference last November when he referred to Cain as behaving "like he's 30."
Asked to elaborate, Lincecum said, "He's a guy that's beyond his years. You think he's been here for 10 years, the way he carries himself with his professionalism and humility. Especially coming from a guy who came out of high school, that says a lot."
Indeed, Cain was only 17 in 2002 when he vaulted to professional baseball from Houston High School in Germantown, Tenn. Yet he displayed much the same maturity he shows now when he reached the Majors three years later. Giants pitching coach Dave Righetti pointed out that Cain ascended through the Minors traditionally, step-by-step from Rookie ball to Triple-A, which furthered his professional and personal education.
"It never hurts," Righetti said. "All that pitching at different levels, buses, early mornings, instructional leagues -- all that's good. But especially for a guy like him."
Barring a surprise, Cain, who's 44-51 with a 3.53 ERA lifetime, will extend his seniority for at least two more years. His four-year contract expires after this season, but the Giants hold a $6.25 million option for 2011 which they'll almost certainly exercise. After that season, the Giants must confront the task of re-signing both Cain, who'll be eligible for free agency, and Lincecum, the two-time Cy Young Award winner who'll be coming off his two-year, $23 million deal but will remain arbitration-eligible.
Though it's still early for Cain to weigh the pros and cons of remaining with the Giants, he and his wife, Chelsea, feel very much at home in San Francisco.
"We love it," Cain said. "We feel very, very comfortable being in the city now. We really love the San Francisco area and all that it has to offer."