SCOTTSDALE — When Tony Vitello finally agreed to take the Giants job, he knew he wanted Quentin Eberhardt to come with him from Tennessee. He also knew he had to sit back and let others come to the realization that one of his close friends would be a strong addition.Eberhardt was Vitello’s director of baseball sports performance at Tennessee, leading the way for a program that was known for being ahead of the curve in terms of strength and conditioning. A few weeks after Vitello departed, he joined a Zoom call with Eberhardt, Buster Posey, Zack Minasian, Jeremy Shelley and Dave Groeschner.He was mostly silent, watching as the whole group came together. The Giants were sold. Eberhardt was, too.“It was kind of a no-brainer, just talking with them and hearing what the vision was and the possibilities,” Eberhardt said recently. “The culture that they wanted to keep restoring was very intriguing. The conversation gave me chills, to be honest.”Eberhardt’s official title in San Francisco is director of performance. He is part of a large group underneath Groeschner, the longtime trainer who recently was promoted to vice president of medical...