The choices are Eli Whiteside and Chris Stewart, both of whom have experience backing up Posey, and Hector Sanchez, 22, who has a lot of offensive potential but is targeted for Class AAA Fresno.
Stewart is on the 40-man roster. Whiteside isn't. But the Giants could always add Whiteside.
One option is a trade, and the Royals are seeking a catcher after losing Salvador Perez to a knee injury.
For now, the Giants want Sanchez to get more experience behind the plate and have him play on a regular basis in the minors.
"It's just a matter of getting time," manager Bruce Bochy said.
Sanchez is a .295 hitter in 319 minor league games. Last year, he hit .302 in 52 games for Class-A San Jose and .261 in 46 games.
With the Giants, Stewart hit .204, Whiteside .197.
--INF Ryan Theriot doesn't have a guaranteed contract, and the Giants could cut him by March 29, in which case they'd need to pay him a quarter of his $1.25 million contract. It would seem Theriot could be a valuable fit in 2012, considering 2B Freddy Sanchez's tender right shoulder and SS Brandon Crawford's questionable bat. Plus, Theriot hit over .300 against lefties last year. But the Giants have two other utility infielders, Mike Fontenot and Emmanuel Burriss. It's questionable whether they'll keep all three.
--SS Brandon Crawford, who swings left-handed, hopes to prove he can hit lefties -- unlike last year. With the Giants, he was 4-for-30 vs. lefties. "I didn't get a whole lot of at-bats against them last year, so when I faced them, it was tough," Crawford said. "It's tough to face a left-hander's slider when you haven't seen one in a couple of weeks." One of Crawford's top moments in spring training was when he homered off a lefty, Seattle's Hong-Chih Kuo.
--RHP Sergio Romo missed some time with an elbow that manager Bruce Bochy called a "little cranky." Romo vowed he was OK and often takes time off in training camp to re-energize the arm, but it must be noted that he was on the DL in August with elbow inflammation and opened 2009 on the DL with an elbow strain. The setup man had the lowest WHIP (0.71) in the majors last year among pitchers with at least 30 innings, and his strikeout-to-walk ratio (14.1) was the majors' best mark since Dennis Eckersley's 18.25:1 in 1990.
--RHP Tim Lincecum is looking forward to his fourth straight opening day start. This one is at Arizona against the defending NL West champs Diamondbacks, who clinched their division title in a game against the Giants. "We've got a remembrance of last year and how they were able to celebrate in front of us. I'm sure a lot of people are itching to get back out there and start the battle over, and hopefully it will be in our favor this time," Lincecum said.
--RHP Brian Wilson experienced fatigue after a St. Patrick's Day appearance, failing to complete an inning. "General soreness" is what manager Bruce Bochy called it. A few days later, he pitched an inning in a minor league game, showing no signs of fatigue. In fact, to benefit Wilson, he threw a little extra and got a fourth out in his minor league inning.
BY THE NUMBERS: 24 -- Pitches Ryan Vogelsong threw in a minor league game, his first game action in spring training, coming off a back strain. It's likely Vogelsong will open the season on the DL because the Giants don't need a fifth starter in the first week.
QUOTE TO NOTE: "He's going to be a star. He IS a star." -- Former Giants catcher Benito Santiago on Buster Posey. Santiago, the MVP of the 2002 NLCS, met Posey during a visit to the Giants' clubhouse.