Coffman was promptly called up to Detroit and joined the Tigers in Philadelphia, and Cochrane told Coffman that he would pitch the first game of a series in Boston. In Boston, Coffman recalled that the newspaper headlines reported that "the young upstart from the cotton fields of Alabama would pitch against the incomparable Lefty Grove." On the day of his debut, Cochrane came into the clubhouse and announced that Eldon Auker would start the game. Coffman complained to Cochrane, "But Mickey you told me I would pitch today, and I'm prepared to do just that." Cochrane responded, "I don't care what I told you. Go out there and bring somebody in like Schoolboy Rowe. Grove's pitching today and I want you to get off to a better start...you know we never score many runs off him." Coffman replied, "Well let me tell you Mickey they won't score many runs off of me, either." Coffman recalled that this was all Cochrane was waiting for, and he slammed his fist on a table and exclaimed, "OK kid I'll catch you." In his first big league start, Coffman got the win against Grove, as the Tigers beat Boston, 4–2. Coffman and Grove both pitched complete games, and Coffman allowed eight hits in 11 innings; he also had a hit in Detroit's 11th inning rally. The Associated Press account of the game opened as follows: "Youthful George (Slick) Coffman, making his big-league debut with the Detroit Tigers, today pitched his teammates to an 11-lnnlng 4 to 2 victory over the Boston Red Sox."