Embley was born in Perth and began his career with Swan Districts in the West Australian Football League (WAFL).

His father is of Anglo-Burmese and Spanish descent and was born in Rangoon, emigrating to Australia in 1964 with his family after the 1962 Burmese coup and settling in Victoria Park.

His father played reserves football for Perth, and also represented Western Australia in the 1973 national junior athletic championships in Melbourne.

He made his WAFL debut for Swan Districts in 1998,[5] and was recruited by the West Coast Eagles with the 57th pick overall in the 1998 National Draft.

Embley made his debut for West Coast in the first round of the 1999 season, a Western Derby against Fremantle, gathering nine disposals and taking three marks.

Embley was named vice-captain of West Coast for the 2004 season, and also represented Australia in that year's International Rules Series.

[9] Despite injuries late in the season, Embley played a key role in the team's successful final series.

He averaged 26 possessions and kicked five goals across the Eagles' three finals matches, despite playing the semi-final against the Western Bulldogs with a paralysed vocal chord.

He was awarded the 2006 Norm Smith Medal as the best-on-ground player in the Eagles' Grand Final win over Sydney for his 26-disposal, two-goal effort.

[17][18] The round eight Western Derby against Fremantle was the only match Embley missed through the entire season, playing 24 out of a possible 25 games, and also recording several personal bests, including career-high numbers in disposals, tackles, and Brownlow votes.

[20] Having successful tested the durability of his shoulder, Embley returned to West Coast's side for the round 20 match against Geelong, starting as the substitute.

[21] He played every remaining game of West Coast's season, recording 22 disposals and four goals in the club's elimination final defeat of North Melbourne.