SAN FRANCISCO (AP) — Tim Lincecum showed up at AT&T Park on Friday with a hooded sweatshirt pulled over his cap and signature shaggy hair, hiding his appearance.

Typical Timmy.

For the first time since signing a new contract that will keep him in San Francisco through the 2013 season, the Giants ace revealed his reasoning behind a shorter deal. He cautioned fans not to worry about his possible pending free agency — both sides are keeping discussions open on a longer contract.

The two-time NL Cy Young Award winner said he'd "love to be a Giant my whole career." He just wants to keep his options open because he has "never been a guy who could make a plan four years from now."

"It's like when someone's like, 'What are you going to be doing? You want to hang out like a month from now when I'm down there?' I'm like, 'I don't know. Just call me when you're down here and I'll see what I'm doing,'" Lincecum said, speaking ahead of Saturday's annual Giants FanFest. "That's the way I've always been. My friends know me that way. My family knows me that way. This is just no different."

Let the countdown begin.

The Giants would love to buy out those first few years of free agency for Lincecum and keep "The Franchise" and "The Freak" as the face of the city's beloved team for the long haul. The front office knows that if Lincecum stays healthy and anywhere close to the success of his recent seasons, San Francisco might not be able to compete with teams such as the Yankees and Red Sox on long-term deals that could pay Lincecum upward of $25 million to $30 million annually.

Lincecum and the Giants completed a $40.2 million, two-year deal last week to avoid arbitration. The contract includes a series of bonuses for awards and milestones and also holds Lincecum to certain agreements, such as purchasing 25 tickets for each home game for charity.

San Francisco still hopes to lock up Lincecum — not to mention strong starter Matt Cain — with a long-term deal.

"It's something that may not happen before the season or even before next offseason, but yes, that is our goal," Giants Vice President Bobby Evans said in a text message.

While the baseball world promises to pay attention to every detail of Lincecum's future, he's focused only on returning to his Cy Young form and taking the 2010 World Series champions back to the fall classic.

Lincecum dropped from an astonishing 197 pounds to 175 this offseason, getting closer to his lanky frame from the 2010 season — where he said he finished at about 157 pounds — and most of his career. The trick? He stopped eating all those hamburgers. He often ordered three double-doubles — with fries and a shake — at a famous California-based fast food restaurant.

"I think I kind of went overboard trying to put on the weight last year," he said.

Lincecum loafed for the first half of the winter in the Seattle area, minus a quick nine-day reprieve on Hawaii's shores. One day, he said, he finally had enough — so he and his friend and roommate started eating healthier and recorded daily weigh-ins on a white board.

Then he went to work.

He tried a new approach, swimming most days in a butterfly stroke — "More like the frog," he joked — to slim down. He said the lack of a longer contract also motivates him to stay at his peak.

"You don't just sit back on your (butt) and be like, 'It's fine, I have that security, so I don't have to worry about getting better next year,'" he said. "I don't want to ever have to do that."

Lincecum has been an All-Star in each of the past four seasons.

He finished 13-14 despite a 2.74 ERA last year, the first losing record of his career. The Giants scored no runs while he was in the game in seven of 33 starts, had one run six times and two runs five times, according to STATS LLC.

Lincecum said the lack of run support has no bearing on his future — if anything, he actually prefers pitching in tight games. The 27-year-old right-hander, the winning pitcher in the Game 5 World Series clincher at Texas in 2010, and Cain consider the camaraderie with teammates in San Francisco paramount.

"There's such a confidence that you can have from a sense of companionship with the other four guys, knowing that maybe not all the pressure is put on you to be the top guy to go out there and win," said Cain, who could become a free agent at the end of the season. "I really do believe in that."

Compensation does matter.

Lincecum acknowledged some of the salaries for top free agents are "semi-ridiculous." He also noted that previous players paved the way for those bloated contracts — including Barry Zito, whose $126 million contract signed in 2007 will saddle San Francisco for another two years — and is only following benchmarks set by others.

That still doesn't stop fans across the Bay Area from peppering the pitcher with questions about his future.

"It's tough to give them the perfect answer to that," he said. "People at this level want to get what they feel like they deserve. I'm not the person who set that line. There have been plenty of people who have set that arbitration line. I'm just working off of it.

"That doesn't necessarily mean that I'm going to leave," he added. "I don't know what's going to happen three years from now. I don't know how I'm going to feel or what's going to happen. A lot of things can happen in a year's time. Given that, the options-open thing is the biggest thing for me.

"It says nothing about not wanting to be here."