SCOTTSDALE, Ariz. -- Right-hander Sergio Romo came down with the Giants' worst injury of the spring thus far, a strained right elbow that will sideline him for 10 more days, manager Bruce Bochy estimated Tuesday.

Romo hadn't pitched since last Thursday, when he allowed six ninth-inning runs (three earned) in a 16-7 loss to the Los Angeles Dodgers. At the time, Romo's lack of sharpness seemed odd, since he had pitched winter ball in Mexico.

Bochy downplayed Romo's ailment. "He had a touch of it last year and was fine," Bochy said.

Given Spring Training's duration, which is about a week longer than usual due to the World Baseball Classic, Bochy said that Romo still has time to pitch himself into consideration for the Opening Day roster.

Romo entered camp as a favorite to claim a bullpen spot after posting a 3-1 record and a 2.12 ERA in 29 appearances last year as a rookie. But Bochy has been impressed by non-roster invitees Brandon Medders and Justin Miller, who both possess Major League experience, and Rule 5 Draftee Luis Perdomo.

"We have some options," Bochy said. "We're probably going to have some tough decisions."

Medders is unscored upon in four innings spanning three outings, while Miller has put together a pair of one-inning shutout efforts. Each blanked the Arizona Diamondbacks for an inning in the Giants' 7-6 exhibition victory Tuesday. Perdomo, who earned the save against Arizona, has compiled a 3.00 ERA and three strikeouts in three games.

In other injury-related news, Bochy described outfielder Nate Schierholtz's playing status as day-to-day. Schierholtz has been bothered by back spasms and hasn't played since Sunday.

Schierholtz's absence has afforded Eugenio Velez more playing time in left field. Velez has seized the opportunity, particularly against the D-backs. He homered in the fifth inning to launch San Francisco's comeback from a 5-0 deficit, added a run-scoring groundout in a four-run sixth and ended the game by diving to snare Chris Roberson's bloop with a runner on second and a run in.

Velez, who's hitting .267, remains a candidate for the second-base job along with Kevin Frandsen (.500, 5-for-10) and Emmanuel Burriss (.417, 5-for-12). Atoning for a fifth-inning throwing error that chased in a run, Frandsen set up a pair of Giants runs by being hit by pitch and executing a sacrifice bunt.

"That's what you like to see," Bochy said of the three-way competition.