Originally an AC Milan youth product, Baresi went on to spend his entire 20-year professional career with Milan, making his Serie A debut at age 17 during the 1977–78 season on 23 April 1978. He had initially been rejected by the Internazionale youth team, who chose his brother Giuseppe instead, hence the Milan youth team signed Franco Baresi. The two brothers ended up captaining their respective teams shortly after, with their image while exchanging pennants became the trademark of Milan's "derby della Madonnina" throughout the 80s.