In his eight seasons, McKinnon caught 194 passes for 3,012 yards and 22 touchdowns. He also returned 129 punts for 1,191 yards and three touchdowns, and scored a rushing touchdown. He caught 31 passes for 555 yards and seven touchdowns during the Bears' championship season in 1985. His best season was in 1988, when he caught 45 passes for 704 yards and three touchdowns, while also returning 40 punts for 405 yards and a franchise record two touchdowns (this record was later surpassed by Devin Hester in the 2006 season). He went on to catch four passes for 108 yards and a touchdown in Chicago's 20-12 postseason win in a game known as the Fog Bowl.
At the time of his retirement, McKinnon's 1,191 punt return yards were the second highest-total in Chicago franchise history.