Burnell led Wales U19 to their so-called 'Grand Slam' triumph over U19 sides from the other five Six Nations countries during the 2005-2006 season and also a Wales U19 double over Australia Schools; this is a role which he has continued to perform to date. In March 2006, Burnell was unveiled as the Head Coach for Cardiff RFC, taking over from Howard Stone at the Cardiff Arms Park. Burnell has had previous club coaching experience in the Principality Premiership with Pontypridd RFC with whom he was appointed Senior Coach during the 2003-2004 season and started his coaching career in 1991 with his home town club of Llantwit Fardre.

As a player Burnell represented a whole host of clubs including Pontypridd, Cardiff, Bridgend, Treorchy and ofcourse the aforementioned Llantwit Fardre; making appearances for Bridgend in the European Challenge Cup between 1996 and 1998. A blindside flanker, Burnell gained international honours with Wales A.