Kearney attended Kingsford High School. He accepted a scholarship from Northern Michigan University. He was a three-year starter at linebacker. As a senior, he received Little All-American honors in 1971.[1]
Kearney was selected in the fourth round (83rd overall) of the 1972 NFL draft by the Dallas Cowboys, who were the defending Super Bowl champions. He faced a difficult challenge in making the team, after the Cowboys drafted a total of 5 linebackers and had one of the best linebacking corps in NFL history already in place. He was waived on September 7, 1972.[3]
On September 1, 1975, he was traded along with Bernard Jackson to the Detroit Lions in exchange for a draft choice, but the transaction was canceled after both players failed their respective physical exams and Kearney was released.[5]
In 1979, he was placed on the injured reserve list with a knee injury after the fifth game of the season.[11] He was released on May 20, 1982, after failing a physical exam with a neck injury.[12]