He's the minor league pitching coordinator. I don't think that position is typically filled by someone with a sparkling resume. The last one, Cory Popham, was hired straight from "Post University" where was the pitching coach for 2 years.
So Lehr has way more experience now than Popham had when he was hired:
Before being the Giants’ pitching coordinator, Lehr worked for the Giants as their rehab pitching coordinator after working as an amateur scout for the Kansas City Royals organization. Following his playing career, Lehr was a professional scout for the Houston Astros until 2014 before joining the Royals.