Stanley was the last active player in the major leagues to have played for the short-lived Seattle Pilots franchise.
Stanley was a key backup to Bucky Dent of the Yankees teams in the late 1970s. He was a favorite player of Phil Rizzuto, who did the color analysis for the Yankees during this timeframe. Since 1960, no other non-pitcher has had as many seasons (nine) with at least 30 at-bats and five or fewer extra base hits.
On October 12, 2007, he was appointed as the Giants' Director of Player Development. Prior to that, he held several positions in the Giants' organization, including spending 2000–2004 as a minor league manager. In 2001, he managed the Salem-Keizer Volcanoes to the league championship of the Northwest League.