OAKLAND -- The Baby Giraffe is growing up and he's poised to take the next step in his career. Brandon Belt, who batted .391 during a stellar Spring Training, is ready to put his disappointing 2011 rookie season behind him.

Belt was in the starting lineup at first base for the fourth straight contest Monday, perhaps a sign he's won the everyday job over Aubrey Huff and Brett Pill. As he looks back on his .225 batting average from a year ago, Belt concedes his struggles were of the mental sort.

"It was nearly 100 percent mental," Belt said. "For me, I think getting in the right mindset is what's going to make the biggest difference. I think I did a lot better job with that this spring than I did last year."

The 24-year-old slugger said he didn't do anything different this offseason and that he focused on getting back to his usual approach at the plate.

"I have a lot more confidence this year," Belt said. "I know a lot more about what to expect coming into this year so there's not going to be too many surprises. I just want to go out there and play my game and see what happens."

Giants approve of Cain's new contract

OAKLAND -- The San Francisco Giants made a bit of history Monday, as they signed Matt Cain to a five-year, $112.5 million contract, making him baseball's richest right-hander by average annual value. Coupled with the two-year, $40.5 million deal Tim Lincecum received this offseason, the Giants now employ the two highest-paid righties in league history by AAV.

While the big figures in Cain's deal could raise the market level for Lincecum in his future contract negotiations, Lincecum doesn't seem to care much.

"The deals work out differently just because we have different agents and they come at different times and they work off of each other," Lincecum said. "It's one of those things where outside of the time when you deal with it, it's not really a factor. I'm not really thinking about it right now."

News of Cain's contract has been well-received in the Giants' clubhouse, as the reliable 27-year-old hurler will be locked up through the 2017 season.

"I think it's awesome that they're bringing in these homegrown players and keeping them for the long haul," teammate Brandon Belt said. "Especially with the stuff he's done the past few years, it's been amazing. I think the organization's going in the right direction."

Posey moved by fans' reception in return

OAKLAND -- If you needed to know how much Giants fans missed Buster Posey, you didn't even have to wait until Monday's first pitch. Playing in front of his home fans for the first time since suffering a season-ending leg injury last May, Posey took the field for warmups to a rousing ovation from the crowd.

"It was one of the coolest things that I've ever been a part of in my baseball career," Posey said. "It was special; it meant a lot."

Posey navigated through Spring Training without incident and looks poised to return to the Opening Day lineup Friday at Arizona, when he will be on the receiving end of Giants ace Tim Lincecum. After seeing the Giants lock up Matt Cain with a lucrative five-year extension Monday, Posey was asked if he could envision himself playing his whole career in a Giants uniform.

"Could I see it? Sure," Posey said. "But, like you said, it's early. It's hard to say if it'll happen or not, but yeah, I could see it. I would love to."

If anyone was happier than the fans to see Posey return, it would be his teammates. Lincecum was sitting in the dugout when Posey took the field Monday and was stirred by the crowd's reaction.

"I was talking to someone and we just heard this uproar," Lincecum said. "We thought a fight had broken out in the stands or something crazy. That was pretty awesome. I'm sure it was good for him and made him feel more welcome."

Worth noting

• Shortstop Brandon Crawford was held out of the starting lineup Tuesday as he recovers from a sprained left thumb. Giants manager Bruce Bochy said Crawford hurt his thumb trying to field a ground ball during Monday night's contest at AT&T Park, but deemed it "very mild" and said Crawford could play if it were a regular-season game. Emmanuel Burriss took over at shortstop, hitting eighth. After the game, Bochy said Crawford would also sit out Wednesday's spring finale.

• Bochy said Barry Zito threw a bullpen session Monday in Arizona as he tries to solve his mechanics by April 9, his first scheduled start. ZIto is slated to make a final tuneup start Wednesday.

"The reports were good on Barry," Bochy said. "... We'll monitor his innings and make sure he gets up to around 90 pitches."

• Bochy said he spoke at length with Giants general manager Brian Sabean on Tuesday. The Giants have until Wednesday to cut their roster down to 25 players.

"I may talk to some guys after the game, if I have time," Bochy said before Tuesday night's game. "But those guys pretty much know if they're going back. We still have some tough calls and probably won't make those until tomorrow morning."