Originally a member of the Queens Park youth set-up, McKenna signed a YTS contract with Clyde in the summer of 2005,[citation needed] and made his début that season, coming on as a substitute in a 5–1 win against Brechin City. This turned out to be his only senior appearance of the season, but he was a regular in the Under 19 side.
McKenna was awarded a professional contract in July 2006, and made more appearances in the 2006/07 season. His first start came against Partick Thistle in November 2006. He was released by the club in May 2008, having only made 2 starts in three years, scoring no goals.[1] He went on to sign for Camelon Juniors. He returned to the senior game in July 2009, joining Brechin City.[2]