Kerr began his professional career with
Partick Thistle in Scotland. When his mother moved to Canada, Kerr followed and emigrated to the
Toronto area before signing with the
Hamilton Steelers/Primos in the
Eastern Canada Professional Soccer League and later in the
National Soccer League (NSL). He also played with
Hamilton Croatia in the NSL. In 1968, he played in the
North American Soccer League with the
Detroit Cougars. In 1969, he joined the
Washington Darts of the second division
American Soccer League where he was a First Team All Star. The Darts moved up to the NASL in 1970 and Kerr remained with the team through the 1971 season. He was the league's 14th leading scorer with Washington in 1971 with 18 points in 24 games. He scored Washington only goal of the
NASL's first-ever indoor tournament in 1971. He also played for New York Hota of the
German American Soccer League when it won the 1971
National Challenge Cup. He also played for
Club América of Mexico in the early 1970s. In 1972, Kerr became a member of the
New York Cosmos. In 1972, he was again the league's 14th top scorer with 10 points in 14 games with the Cosmos and was named league First Team All-Star at midfield. He then played the 1976 and 1977 seasons with the
Washington Diplomats, serving during the 1977 season as an assistant coach. However, on 17 July 1977, the Dips informed Kerr that the team planned to release him. ==International career==