SCOTTSDALE, Ariz. -- Asked Thursday whether his experience so far with the Giants had bolstered his confidence about making the Opening Day roster, Kensuke Tanaka replied, "I don't know, but I want to try my best to succeed."

That summarized Tanaka's situation with the Giants: uncertainty mingled with earnestness.

There's no doubt that Tanaka, who's in camp as a non-roster invitee, can thrive at second base. During his 13-year career with the Nippon Ham Fighters in Japan, he was named the top player at his position in both professional leagues four times. He also won three Gold Glove Awards for defensive excellence.

But to begin the regular season with the Giants as a utility man, the 31-year-old Tanaka must prove that he can function adequately on the infield's left side. That includes shortstop, where he looked challenged during the Giants' 6-3 loss to Japan's national team, which visited Scottsdale Stadium for a tuneup en route to the World Baseball Classic semifinals in San Francisco.

Tanaka called the experience of starting against his countrymen "fun and energizing." But he committed a third-inning throwing error and made a one-hop toss to first base on Yoshio Itoi's routine ground ball leading off the fourth inning. Tanaka partially atoned later by starting an inning-ending double play in the fourth and turning another double play in the fifth.

Tanaka has been forced to familiarize himself with America's grass-and-dirt fields after playing mostly on artificial turf in Japan. But reserve infielders are expected to make every play. And Tanaka has committed seven of the Giants' 15 errors this spring.

"He has a lot on his plate right now. We've thrown a lot at him," Giants manager Bruce Bochy said. "We thought, with as much as we're moving him around, that we'd probably see some errors that would come with the change in position."

With bullpen catcher Taira Uematsu serving as an interpreter, Tanaka admitted that he has had to adjust to "the distance of the throw and also the direction of the ball coming from the hitter" when playing shortstop. Bench coach Ron Wotus, who supervises the Giants' infielders, further explained the difficulty of moving from second to short.

"Probably the toughest thing about going from second to short is that your game clock is different," Wotus said. "At second base, you have a lot of time to field the ball and get rid of it. At shortstop, you don't have that time. You have to catch the ball and get it to first in a more efficient manner. Your arm comes into play with that."

Fortunately for Tanaka, the language barrier has rarely interfered with his efforts.

"It's OK with players during the game," he said.

Tanaka's diligence and aptitude are beyond reproach.

"He's very intelligent, and to say the least, he's a hard worker," Wotus said.

Asked if he'd accept an assignment to Triple-A Fresno to begin the season, Tanaka said, "Probably." That's quite a concession, given Tanaka's level of stardom in Japan. His willingness to embrace a backup role is obviously sincere.

"Shoot, that's half the battle," Wotus said. "He has an opportunity to be good at it. But it's not easy, and it's going to take time."

Sanchez again sidelined with shoulder pain

SF@LAA: Sanchez ropes an RBI double to left field

SCOTTSDALE, Ariz. -- Recurring soreness in catcher Hector Sanchez's right shoulder will force him to rest for at least a couple of days.

Sanchez was scratched from Thursday's starting lineup against Japan. Manager Bruce Bochy had hoped that Sanchez could serve as the Giants' designated hitter. But swinging a bat pained Sanchez as much as throwing did.

Due to the fluctuations in Sanchez's health, "there should be some concern at this point," Bochy said.

Guillermo Quiroz, who has played in the Majors for five teams in nine seasons, likely would become San Francisco's backup catcher if Sanchez were sidelined for a prolonged period. Bochy also cited Jackson Williams, who has spent six years in the Giants' Minor League system, as a possibility.

"We think we have some coverage there," Bochy said.

Johnny Monell, another catcher, will have to maintain his torrid hitting (.600 in Cactus League games) to keep pace with Quiroz and Williams. Monell also has logged six years as a Giants farmhand while playing all but five games below the Triple-A level.

"He's made a lot of noise here. He's done a pretty good job," Bochy acknowledged. "He'll get more catching time. We're not ruling anything out. We like his bat. It works."

Sanchez was aching before he even changed into his uniform.

"It scared me, because it felt really painful," he said. He added that the team's medical staff told him that he had no structural damage in the shoulder.

After showing promise last year by batting .280 in 74 games, the switch-hitting Sanchez has appeared in only eight of San Francisco's 19 games this spring. He owns a .211 average (4-for-19) with three RBIs.