Obst joined Whitehaven in 2004 and was voted National League One Player of the Year for 2004. He went on to join Wakefield Trinity Wildcats.
Wakefield Trinity Wildcats
The Australian had an excellent season with the Wakefield club, especially during the latter half of 2006 under John Kear. He later re-signed with Wakefield Trinity Wildcats for another two years to keep him as a player there till 2009. He later signed a new two-year deal by head coach John Kear, and has accepted, keeping him at the club until 2011. In 2008 and 2009, Obst received the club's man of steel (best player for club).
On 1 December 2011 it was announced that Obst had signed a 12-month deal with Co-operative Championship club Keighley Cougars. Obst followed in his father's (Tony Obst played for Keighley in the 1970s) footsteps and re-joined two of his former teammates in Michael Korkidas and cougars player-coachJason Demetriou.
Northern Pride
In 2013 Obst played for the Cairns based Intrust Super Cup team, the Northern Pride. In 2014, Obst was part of Northern Pride's Queensland Cup winning side. Obst played in the inaugural NRL State Championship final for the Northern Pride as they defeated Penrith 32–28. He played with the club up until the end of the 2015 season.[2][3] In 2017 he returned to the Pride as assistant coach, a role he still holds (2024).