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