Despite being in his 13th season, the 31-year-old continues to play an important role, having averaged 19 disposals and one goal through his 11 matches.
The potential of a premiership drives him.
"I've always said being a one-club player is something that would be pretty special to me," Douglas told afc.com.au.
"We've got a highly determined playing and coaching group who are driven towards achieving the ultimate success.