For Walt Weiss, the benefit of a bolstered bullpen is having the luxury to plan ahead. The Rockies were 19-0 this season when taking a lead into the eighth inning. On Saturday, that played to plan again — until it fell apart. But in relying on rookie right-hander Carlos Estevez in a high-leverage situation, Weiss tipped his hand to how the Rockies might move forward with their relief corps. Colorado carried a 5-4 lead into the eighth Saturday before Estevez — who was called upon for a third appearance in three days — gave up three runs in a six-run inning as the Giants rallied late for a 10-5 victory. Estevez’s entry was decided before the game. “With the lead, we’re going with Estevez,” Weiss said of the 23-year-old who was called up in late April.