Matt Cain has been called up to start Monday night's game against Colorado. He is the Giants top prospect. "I had a smoothie," said Cain, whose three-year ride from high school through the minor leagues could not have been smoother than his beverage. On Friday, the Giants purchased Cain's contract from Triple-A Fresno and said he will replace starter Brett Tomko, who returns to the bullpen. "I believe the organization is making a transition, making a move," manager Felipe Alou said. "The players are there, especially the young pitchers, and they are being given an opportunity." General manager Brian Sabean said the Cain and Taschner promotions are "signaling an effort to try to win some games. The bottom line is to try to win and develop. The young kids are ready in our estimation. For that you're going to have to change the makeup of your roster."