Karl played as full back for City reserves at Yeovil in 2007.

After coming through the ranks at QPR, where he made it to the reserve team, he was released at the end of the 2007-08 season. He played for Wales Under 19's whilst at QPR.

Karl played 21 times for Poole Town in 2008 and later in the season played 7 games for Wealdstone

He joined Weston Super Mare at the start of the 2010 season, joining Lowestoft Town in the Ryman League a little later.

After a spell at Hamworthy, he joined Christchurch for the 2012/13 season.

He was playing at Christchurch in 2018/19.