© 2013 MLB Advanced Media, L.P. All rights reserved.

04/10/2013 4:20 PM ET

Rosario displays speed with two stolen bases

SAN FRANCISCO -- Rockies catcher Wilin Rosario, who hit 28 home runs last season as a rookie, is known most for his extraordinary power at the plate.

Rosario showed off one of his under-the-radar skills Tuesday night, stealing a pair of bases against the Giants.

"I can run a little bit, and I take advantage," Rosario said before Wednesday afternoon's series finale against the Giants at AT&T Park. "Sometimes they get a little comfortable on the mound, and I get the advantage."

Rosario took advantage of San Francisco starter Tim Lincecum's slow delivery both times. After a second-inning walk, Rosario got such a good jump that Giants catcher Hector Sanchez didn't even make a throw. Then after singling in the sixth, Rosario took off again and beat Sanchez's throw.

Rosario stole only four bases last season in 117 games. How many can he steal this year?

"I don't know, because the year, it's just starting right now," Rosario said. "Maybe 10. Maybe nine."

Rosario already has three home runs, and he has earned rave reviews from manager Walt Weiss.

"He's one of those guys that's got different power and a different sound to his bat when he hits the ball," Weiss said. "He's got a chance to be a superstar."

Rosario said that's his goal.

"Oh yeah. I'm working hard," he said. "I want to be one of those guys everybody's talking about and saying a lot of things positive. I want to work hard and learn as much as I can, ask a lot of questions."

Rockies struggle vs. Romo, with exception of Rutledge

SAN FRANCISCO -- It's no secret how tough Giants' closer Sergio Romo can be on opposing hitters with his nearly unhittable slider.

In the first two games of their three-game series with San Francisco, the Rockies faced Romo twice. He faced seven Colorado hitters and struck out five, while logging two saves.

Second baseman Josh Rutledge was the only Rockies player with a hit off Romo this season entering the series finale Wednesday afternoon at AT&T Park. In the ninth inning of a 4-2 loss Monday night, he rocked Romo's first pitch high off the wall in left-center field for a double.

"It was a slider," Rutledge said. "Kind of a little out over the plate."

Romo rarely makes location mistakes with his money pitch, so Rutledge jumped on it.

"He does a real good job of keeping his pitches down," Rutledge said. "He gets a lot of swing-and-misses, too. He's a tough guy to face. I was really just going up there and trying to get on base any way I could. He happened to give me something I could put a good swing on."

After Rutledge doubled, Romo struck out Chris Nelson, Todd Helton and Wilin Rosario in order to end the game. In the ninth inning of a 9-6 loss to San Francisco on Tuesday night, Reid Brignac grounded out to Romo while Eric Young Jr. and Dexter Fowler struck out to end the game.

In his career against the Rockies, Romo is 1-0 with a 1.88 ERA and three saves. He has 30 strikeouts in 24 innings pitched, averaging 11.3 strikeouts per nine innings.

Worth noting

• Jordan Pacheco started at first base Wednesday for the Rockies in place of the struggling Todd Helton. Helton is hitting .095, with just two hits in 21 at-bats. Pacheco is hitting .375 (3-for-8) after hitting .309 last season, topping all National League rookies.

• Center fielder Dexter Fowler was out of the starting lineup Wednesday for the first time this season, receiving a well-deserved breather. He's batting .317 with four home runs, seven RBIs and eight runs scored. Eric Young Jr. got the start in center field.

• Rockies shortstop Troy Tulowitzki, a San Francisco Bay Area native, hit his 13th career home run against the Giants on Tuesday night, a solo shot off Tim Lincecum in the fifth inning. Since 2007, only the Dodgers' Adrian Gonzalez has more homers against San Francisco with 14.

Eric Gilmore is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.