MILWAUKEE — Hundreds of pitchers will be fortunate enough to stand on a major league mound every season. Only a small fraction of them, if they are honest with themselves, will develop a true and firm identity out there.The best hitters in the world have something to do with that. They have a way of putting an unestablished pitcher on the defensive, making them react and adapt, forcing them to focus on external stimuli and distracting from their internal strengths. Logan Webb came through that shaky phase early in his career with the San Francisco Giants. Along the way, he figured out a sinking, two-seam fastball that took the launch out of everyone’s launch angle. He developed a changeup that harvested even more weak contact. While leading the National League in innings in each of the past three seasons, his sense of self became as durable as his right arm.But there are times when even an elite groundball pitcher needs some extra grounding.So Webb stretched out his pre-start meditation session to a half-hour Wednesday afternoon. He let Quentin Eberhardt, the Giants’ director of player performance, guide him through breathing techniques and mindfulness exercises. He walked barefoot in the outfield grass. In the most direct sense, he was preparing to face the Milwaukee Brewers, who have one of the most relentless and uncharitable lineups in the league. Indirectly, he was preparing for an even greater challenge.That’s because Webb was making just his second start since returning from his first stint on the injured list in five years, and the Giants rotation, missing their load-bearing wall, had crumbled in his absence. The pitching staff wasn’t merely ineffective while the Giants plunged to the bottom of the NL West standings. They had become erratic and inefficient, issuing walks and then holding hands to hips while baserunners scored. The staff had abandoned all the tenets that Webb had modeled every fifth day. The Giants had lost their sense of self.It wasn’t fair to expect Webb to restore it all by himself. But if he didn’t start the rebuilding process, who else would?“I feel like I really haven’t done my job as a leader, and — I hate the word ace, to be honest — (as) the ace of the staff,” Webb said after Wednesday’s game. “I feel like I’ve not led it the right way, just in my performance. And to be able to get healthy, feel better, and throw the way I feel like I should throw every time, it was nice.”