SURPRISE, Ariz. -- Manager Bruce Bochy reiterated Sunday that he expects to have "a real good idea" about the composition of the Giants' starting infield by Tuesday, when they break camp in Arizona.

But envisioning how the Giants can accomplish this is difficult. With Opening Day in Los Angeles looming next Monday, no infield spot is truly set.

Ray Durham, the presumptive starting second baseman, and Kevin Frandsen, a utilityman who has an outside shot at playing third, remained sidelined by their respective injuries. This complicates the Giants' decision-making. Bochy indicated that either, or both, could begin the season on the 15-day disabled list if their ailments linger.

Dan Ortmeier lifted his spring batting average to .238 with a sixth-inning RBI infield single in the Giants' 5-2 loss to the Texas Rangers, but he likely must do more to clinch the first-base job. Whether Rich Aurilia will start at third or first probably depends on Ortmeier's fate.

It has been assumed that rookie Brian Bocock will serve as the temporary shortstop while Omar Vizquel's left knee heals, yet newly acquired Jose Castillo started there Sunday.

Although the prospect of Castillo starting somewhere for the Giants in the season opener appears unlikely, the injuries to Durham (tight left hamstring) and Frandsen (left Achilles tendinitis) have forced the Giants to experiment at this late juncture. Castillo, claimed on waivers Saturday from the Florida Marlins, hadn't played shortstop all spring until now, and he's tentatively slated to start at third base Monday against the Arizona Diamondbacks.

"I don't care what position I play," Castillo said, hungry for employment.

Castillo received an endorsement from Vizquel, his Venezuelan Winter League teammate at Caracas during the offseason.

"Wherever we played him, he did a great job," Vizquel said.

Frandsen, although Castillo's presence could diminish his playing time, acknowledged the club's need for another infielder.

"They have to do everything possible for every situation," Frandsen said.

Castillo, who moved to third base in the eighth inning against the Rangers, neither distinguished nor embarrassed himself. He handled four chances flawlessly and started two double plays while going 1-for-4.

"He was fine," Bochy said. "I'm sure with the travel and everything, he's had a lot going on."

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Castillo, Pittsburgh's regular second baseman from 2004-06, might find himself at that spot if Durham can't return soon. The 36-year-old missed his fourth consecutive game but participated in a workout at the Giants' training base in Scottsdale. He insisted that his health isn't a concern.

"I'll be ready for Opening Day," Durham vowed. "We're just being smart about it, making sure this thing is 100 percent at the start of the season instead of favoring the leg and something else starts to get sore or something else happens."

Durham has been scratched twice from the lineup while being idled and could add to that total, since he's penciled in the batting order for the Arizona game. Bochy and athletic trainer Dave Groeschner plan to check on Durham's condition Monday morning.

"Talking to 'Gresh,' it's iffy," Bochy said of Durham's playing status. "We need to get him out there."

Bochy was more upbeat about Frandsen, who will play third base for four or five innings in a Minor League game in Scottsdale on Monday.

"He looks like he's turned a corner," Bochy said.

Meanwhile, the legend of rookie Eugenio Velez continued to grow. Despite going 0-for-3 while starting at second base, Velez drew two walks and clearly made the Rangers nervous when he was aboard. Velez also has begun drawing chants of "Ooo-genio" during his plate appearances, reminiscent of the "Ooo-ribe" salute that fans showered upon Jose Uribe, the late Giants shortstop.

The Giants also face bullpen decisions. After Tim Lincecum pitched six sharp innings, allowing two runs and striking out seven, Erick Threets allowed a pair of seventh-inning runs, enabling Texas to snap a 2-2 tie. It was only Threets' second appearance since March 12. He's also out of Minor League options, as is right-hander Merkin Valdez, another bullpen candidate. It's all a complex mix for the Giants' braintrust to consider.