April 8 – One-handed pitcher Jim Abbott makes his major-league debut with the California Angels, without spending a single day in the minor leagues. He went on to a 12–12 record for the season.
August 10 – Ten months after undergoing surgery for cancer in his pitching arm, San Francisco Giants pitcher Dave Dravecky returns to the major leagues, winning his comeback 4–3.
August 15 – Dave Dravecky's comeback bid ends when his pitching arm breaks in the sixth inning of his second start. Two years later, the cancer-stricken arm would be amputated.
August 24 – Following an investigation that he gambled on baseball, superstar player Pete Rose is banned from baseball for life.