Stokes was handed a raft of sanctions after he was arrested and charged by Victoria Police for possessing and trafficking cocaine on February 3, including only being able to train at Skilled Stadium when no other players are present.
Bell Park coach and former Geelong player John Fitzgerald, who played eight games with the Cats from 1986-87, said the addition of Stokes would assist all concerned.
"He will be a positive person around the club," Fitzgerald told geelongcats.com.au. "Both Mathew and our players will benefit from the experience.
"Our club's leadership group, our coaches and the committee all discussed this and we were unanimous in the view that we should extend this opportunity to Mathew.
"As members of the community it is important to recognise there are chances to help people make their lives better and we think that this will help Mathew both in and outside of football."
From rounds one to four of the AFL season, Stokes can train just with Geelong's VFL-listed players and he can rejoin the VFL squad from rounds five to seven.
From round eight Stokes will be eligible to train with Geelong's full squad and be available for AFL selection.
A $5000 fine - the maximum sanction under the AFL players' code of conduct - was also issued to Stokes. He must also find employment and conduct any training outside of working hours from now until round four.
Stokes must also establish a relationship with a drug-related community program and assist with it on an ongoing basis.
The 25-year-old has played 71 matches for Geelong since debuting in 2006.
Mathew Stokes is a $322,000 forward in this year's Toyota AFL Dream Team.