Western Bulldogs (2005–2014)

Touted among the best players on offer in the 2004 AFL draft, the Western Bulldogs selected Griffen third overall as a priority pick. He had represented South Australia in the 2004 AFL Under 18 Championships and played senior football for SANFL club South Adelaide in his draft year.

Griffen made his debut in Round 4 of the 2005 AFL season against the West Coast Eagles at Subiaco, where the Bulldogs were defeated by the Eagles by 36 points. He played 17 games in his first season as a Bulldog.

The 2006 Record describes Griffen as a "defender, both in a man-marking role and as a launching pad for attacking moves". Griffen has already displayed a good deal of the latter at the midway point of the 2006 season and most football critics anticipate that he will have a long career.

He suffered a jarring knee injury in Round 11 2007, where he dislocated his kneecap in the win over the Brisbane Lions. The extent of the injury, in itself, was not season threatening although he did suffer complications from a twisted bowel, which hampered his recovery and ruled him out for the rest of the season.

In 2008, Griffen played 24 games spending more time in the midfield, averaging career highs in disposals, contested and uncontested possessions, inside 50s and clearances. He covered plenty of territory and ranked number one at the Bulldogs in inside 50s and rebound 50s combined. He also ranked third in the AFL for running bounces and equal fourth at the Bulldogs for score assists during the H&A rounds. The speedy midfielder broke open a number of games in 2008, earning maximum Brownlow votes in consecutive matches against St Kilda and Essendon in rounds three and four. Finished second in the AFL for bounces and top 10 in the Bulldogs’ best and fairest. In 2009, Griffen played well at times, winning three Brownlow Medal votes on multiple occasions, but many believe he hadn't reached his full potential.

Griffen was one of the players who spoke out regarding Jason Akermanis' controversial sacking midway through 2010 season.^[1] In the Round 14 match against Hawthorn, Griffen failed to make an effort to take a mark against Xavier Ellis 30 metres out late in the final quarter as the Hawks came from behind to win by 3 points, and he was widely criticised. Griffen made up for his mistake the following week when he was named among the Bulldogs' best in a 68-point thrashing of Carlton.^[2][3] On the eve of the finals, Griffen was shifted from his customary position on the wing into the midfield to replace injured teammate Adam Cooney. Although the Bulldogs were again bundled out in the Preliminary Final, Griffen was one of the stand-outs, averaging 28 possessions across the three games.^[1] At the end of the season he was proclaimed the winner of the 2010 Charlie Sutton Medal.

Greater Western Sydney (2015–2018)

At the end of the 2014 season, Griffen asked to join the GWS Giants. On 15 October a trade was successfully reached, reuniting Griffen with coach Leon Cameron, and players Dylan Addison and Callan Ward.

In round 3, 2017 Griffen suffered a syndesmosis of the left ankle, which left him unable to play for the rest of the home and away season. He made his return in a scratch match between the Giants' reserves and Adelaide's reserves the day after their qualifying final.^[5]

Griffen announced his retirement from AFL football following the Giants' semi-final loss to Collingwood on 15 September 2018.^[6]