SAN FRANCISCO -- Shortstop Edgar Renteria was placed on the 15-day disabled list Wednesday with a strained right hamstring suffered during the Giants' 4-2 victory over the Washington Nationals on Tuesday night.

"He's pretty sore there," Giants manager Bruce Bochy said Wednesday. "This is not good news for us. We just got him back and he was playing well."

After Wednesday's 7-3 loss to the Nationals, the Giants announced they were calling up infielder Ryan Rohlinger from Triple-A Fresno.

Renteria, who was 4-for-10 with an RBI in three games since returning from his last stint on the disabled list with a strained groin muscle, pulled his right hamstring while running to first base on a seventh-inning sacrifice bunt.

"We'll probably have to take a little time to get him back on the field," Bochy said. "We're talking about another player."

In addition to utility man Juan Uribe and Rohlinger, Bochy's options at shortstop include using Matt Downs or Freddy Sanchez on a short-term basis.

"Matt has taken ground balls there," Bochy said. "He's been working there. Even Sanchez could do it for a game."

Schierholtz better, back in starting lineup

SAN FRANCISCO -- Nate Schierholtz doesn't like to make excuses, but it's no stretch to say the injured right shoulder that has plagued the Giants outfielder since late April has played a part in his struggling bat.

Schierholtz was hitting .306 on April 27 before diving to make a catch against Philadelphia. After going 5-for-5 the following day, Schierholtz has been mired in an offensive slump, hitting .237 (14-for-59), and entered Wednesday having played just two of the Giants' past five games, entering both as a late-inning defensive replacement.

Schierholtz received a cortisone shot earlier this week to help the injured shoulder -- which he said consisted of a bruised rotator cuff and also some tendinitis -- and started in right field for the Giants on Wednesday.

"I could feel it at the plate. Holding my bat on my shoulder, it just didn't feel right," Schierholtz said. "I tried to play through it, but I had an opportunity to play -- which I didn't have at the beginning of the season. If I had to do it over, I probably would've said something earlier, but it's just something that you hope goes away and this one didn't."

Burriss tests healing foot by running bases

SAN FRANCISCO -- Giants infielder Emmanuel Burriss ran bases Wednesday for the first time since refracturing his left foot in Spring Training and said he hopes to be back on a baseball field in approximately two weeks.

"It's coming along good," Burriss said of the foot. "It's pretty much on schedule. I haven't had any news-breaking scenarios with the foot, so it's pretty much been on track."

Burriss, 25, opened last season as the Giants' starting second baseman before being demoted after a slow start at the plate. While at Triple-A Fresno, Burriss broke the fifth metatarsal in his left foot while running the bases on July 5. In the team's Spring Training opener on March 3, Burriss refractured the foot legging out a double.

After breaking his foot twice within a nine-month span, Burriss said the biggest obstacle he must overcome is his confidence.

"There were a couple times on the bases where I got close to the base and I just got nervous," Burriss said. "That's something I have to get rid of."