He was also named at centre in the Super League Dream Team, and was short-listed for the Man of Steel award along with Trent Barrett and James Roby.

In 2009, he wore the number 8 jersey for Wakefield Trinity Wildcats, in memory of his close friend Adam Watene.

In 2010, he was awarded a 3-month testimonial at the Wakefield Trinity Wildcats as a reward for his hard work and dedication to English rugby league.

He initially joined the York City Knights for 2011, but a subsequent offer as player-coach for Keighley Cougars arose, and was accepted.

During his two seasons at the Pride, the club won back-to-back minor premierships, the 2014 Queensland Cup Grand Final and the inaugural NRL State Championship game.

[9] On 4 October 2015, Demetriou was a member of the North Queensland coaching staff in the side's 17–16 Grand Final victory over Brisbane.

[14] In February 2020, it was announced that Demetriou would succeed Bennett as head coach at the end of the 2021 NRL season.

[17] Following the conclusion of the 2021 NRL season, he replaced the outgoing Bennett as the new head coach of South Sydney.

[21] Ahead of the clubs round 6 game against Cronulla, it was reported that Demetriou would be sacked as South Sydney head coach if they failed to win the match.

[22] On 30 April 2024, the club formally terminated Demetriou as coach, appointing Ben Hornby as an interim for the remainder of the season.

[23] On 27 August 2024, it was reported that Demetriou had been appointed coach of the men's Papua New Guinea national rugby league team.