Keenan started his career with English giants , but suffered a broken leg playing against Arsenal Reserves in October 2002. He made his first-team debut for during 2002 as a substitute for John Terry against , before his second appearance came as a replacement for Gianfranco Zola in an FA Cup tie.
He played as a left wingback for Australian champions Melbourne Victory FC, but he can also play anywhere across midfield. Keenan went on trial at Scottish Premier League side and signed for them in July 2008. He scored his first goal for the club in the CIS Cup against Morton.