Mike Shannon, a native of St. Louis, Missouri, embarked on his Major League Baseball career with the St. Louis Cardinals. Initially, Shannon's athletic prowess was evident during his high school years at Christian Brothers College High School, where he excelled in multiple sports. His talent on the field caught the attention of the Cardinals, who signed him in 1958.

Shannon's journey to the major leagues began in the minor leagues, where he honed his skills and prepared for the challenges of professional baseball. He made his MLB debut with the Cardinals in 1962, starting as an outfielder. His early years in the majors were marked by his adaptability and willingness to learn, which eventually led to a shift in his playing position.

In 1964, Shannon became the Cardinals' regular right fielder, a move that coincided with one of the most memorable seasons in the team's history. That year, the Cardinals clinched the National League pennant and went on to win the World Series against the New York Yankees. Shannon's performance in the World Series was commendable, as he hit a crucial home run in Game 1, helping set the tone for the Cardinals' victory.

As the Cardinals sought to strengthen their infield, Shannon transitioned to third base in 1967. This position change proved beneficial for both Shannon and the team. His defensive skills at third base were instrumental in the Cardinals' success that season. The team once again captured the National League pennant and faced the Boston Red Sox in the World Series. Shannon's contributions were vital, as he hit another significant home run in Game 3, aiding the Cardinals in securing their second World Series title in four years.

Throughout his career, Shannon was known for his strong arm and powerful hitting. His ability to perform under pressure was evident in his postseason appearances, where he consistently delivered key plays. In 1968, Shannon and the Cardinals returned to the World Series, this time facing the Detroit Tigers. Although the Cardinals fell short, Shannon's performance remained a highlight of the series.

Unfortunately, Shannon's playing career was cut short due to health issues. In 1970, he was diagnosed with nephritis, a kidney condition that forced him to retire from professional baseball. Despite the premature end to his playing days, Shannon's time with the Cardinals left a lasting impression on the team and its fans.

After retiring as a player, Shannon transitioned to a successful career in broadcasting, becoming a beloved voice of the Cardinals for decades. His deep connection to the team and the city of St. Louis continued to resonate with fans, as he shared his insights and experiences from his playing days.