In August 1975, Claiborne resigned his Oakland post. He then joined the Red Sox as a special assignment scout, evaluating West Coast-based teams at the major league level. When Boston won the American League East Division and faced the three-time defending world champion Athletics in the 1975 American League Championship Series, Claiborne's scouting report was a critical factor in Boston's stunning three-game sweep. At season's end, he was promoted to chief aide to Bosox general manager Dick O'Connell.