PHOENIX -- In a move that will give the Giants an active roster with 12 pitchers, the club placed infielder Ryan Theriot on the 15-day disabled list on Friday with right elbow inflammation and called up reliever Shane Loux from Triple-A Fresno.

Theriot had been playing through the nagging injury, but an MRI on Friday revealed a more serious problem. In 24 May at-bats, Theriot had just two hits.

"It goes back to Spring Training," Giants manager Bruce Bochy said of the elbow. "It got better, then we found the sprain today."

Loux last pitched in the Major Leagues with the Angels in 2009, when he made 18 appearances and had a 5.86 ERA over 58 1/3 innings.

In Fresno this season, Loux was dominant out of the bullpen. In 21 innings, he allowed just one earned run, with batters hitting .157 against him.

Even more attractive to the Giants is that Loux is able to throw multiple relief frames at a time. Of his 13 appearances this season, only four of them were for one inning or less.

"We need someone to give us multiple innings," Bochy said. "We're better off going with 12 pitchers. He was throwing the ball well."

Bochy checks in on Sanchez in Arizona

PHOENIX -- In town for a three-game series with the D-backs, Giants manager Bruce Bochy stopped by an extended spring game on Friday to watch rehabbing Giants infielder Freddy Sanchez and pitcher Eric Surkamp play.

"[Sanchez] made a couple plays, he looked alright," Bochy said. "[Surkamp] threw the ball pretty well. He gave up a home run, but looked OK."

Recovering from a right shoulder dislocation, Sanchez, who played 58 games last season at second base, was at third base Friday.

Bochy said the 34-year-old asked to play that position.

"That's what we're talking about now," Bochy said. "[The positions] all have different plays, but at third base, you have momentum going to the bag."

With regular third baseman Pablo Sandoval expected to miss four weeks with a broken bone in his left hand, Sanchez could see time at third when he returns to the Giants, which is projected to be before Sandoval.

Sanchez went on a rehab assignment with Class A Advanced San Jose on April 23, but he appeared in just three games before returning after feeling a strain in his shoulder.

Vogelsong gets injection, says back is fine

PHOENIX -- Giants pitcher Ryan Vogelsong had an injection in his back on Thursday, but said the procedure was done for maintenance, not because of any discomfort.

"It wasn't mapped out, but I was scheduled to get another injection during the season," Vogelsong said. "[Thursday] was just a good day for it. I'm doing fine, no issues. I'm fine for a 34-year-old."

Giants manager Bruce Bochy verified Vogelsong's health and the pitcher went along with his regularly scheduled bullpen session Friday.

"It's hard to feel better when there's nothing going on," Vogelsong said of his back, which nagged him during Spring Training. "There's nothing to do, I'm not worried about it."

In 33 2/3 innings this season, the right-hander has a 2.94 ERA, with 26 strikeouts and two home runs allowed.

His last outing came against the Dodgers on Tuesday, when he gave up one earned run on eight hits over 7 1/3 innings to outduel Clayton Kershaw.

"At times I felt like I didn't have the best stuff, but I got outs -- that's what pitching is," Vogelsong said. "Obviously, it wasn't just me the other night; the defense helped me out."