Arias proved last season that he can perform capably at third base, where he started 39 games. Obviously, the Giants hope that Sandoval's inflamed right elbow heals enough by the weekend to allow him to rejoin the lineup for the April 1 season opener at Los Angeles. But if Sandoval mends slowly or sustains a different injury at another juncture, the Giants can summon Arias without a trace of anxiety.
"He's just what you're looking for in a utility infielder," said Giants bench coach Ron Wotus, who supervises the club's infielders. "You want somebody, who, when you put him in the game defensively, he's not going to hurt you. And he contributes offensively as well. He's perfect for what we need."
The Giants might prefer needing Arias less than they did last year. Marco Scutaro is expected to be a fixture at second base, where Arias started twice a year ago. Brandon Crawford has established himself at shortstop, where Arias received 38 starts in a quasi-platoon. And San Francisco is banking on Sandoval, who sustained broken hamate bones in each hand during the previous two seasons, to stay healthy enough to provide the power that made him the Most Valuable Player of the World Series.
Then again, the 37-year-old Scutaro probably will require occasional rest. The left-handed-batting Crawford likely will be excused from the lineup when the Giants face left-handers who are particularly formidable or struggle against right-handed batters such as Arias. Sandoval missed 99 games in 2011-12. At some juncture, Arias, whose background as a shortstop accounts for his versatility, will become essential.
He's ready to be summoned. Formerly a top prospect with the Yankees and Rangers whose progress was derailed in 2007 by an injured right shoulder, Arias appeared in 112 games last year, virtually doubling his career total of 113 entering the season.
"I feel like I'm part of the team," Arias said, with outfielder Andres Torres serving as a Spanish-speaking translator. "I got the opportunity I never had with other teams. My confidence is really high right now."
The Giants reciprocated Arias' confidence by using him in critical situations.
Manager Bruce Bochy employed Arias as a defensive replacement in 12 of the club's 16 postseason games last year.
"He can play third like a shortstop," Wotus said. "He can play deep, and he's outstanding on the slow roller. It's an upgrade for us when he comes in at third base."
Arias should perform even better this year. Still bothered by shoulder soreness at the outset of the 2012 season, he estimated that he threw with about 75 to 80 percent of his usual effectiveness for much of the season. Now, he said, "I feel 100 percent."
Arias also hit a Major League-high .417 (minimum 50 plate appearances) in August, when the Giants were still striving to wrest control of the NL West from the Dodgers.
"He battles you at the plate and gives you productive at-bats," Wotus said of Arias, who batted .270 overall.
Arias' calm demeanor helps him cope with pressure situations while coming off the bench.
"I treat everything the same," he said.
That's why the Giants are bound to count on him some more.