Born in Rotherham, South Yorkshire, Merris was a member of the youth system of hometown club Rotherham United before joining Guiseley in 1998. He joined Harrogate Town in September 1999, with whom he won the Northern Premier League First Division title in the 2001-02 season. Dave made 148 appearances and scored 11 goals for Harrogate during this period.
Merris has gone on to play for a number of clubs in Yorkshire during his career, such as York City, Harrogate Town and Guiseley.
The defender joined NPL Division One North club Ossett Town as a player coach in June 2014 and was appointed player-assistant manager in November 2014.
Merris played for Steve Kittrick when he managed Guiseley before joining the Ingfielders in the summer of 2014, and this connection brought Dave to Scarborough Athletic in 2016.
Dave has proved an excellent signing in defence with his composed displays, whilst not afraid to get down the left wing when attacking to provide a cross into the box.