That paves the way for Joseph to sign with the Saskatchewan Roughriders, then announce his retirement after 11 CFL seasons. Joseph enjoyed his best campaign with the Riders in '07, being named the league's outstanding player before leading the team to a Grey Cup victory in Toronto.
"I will speak to media about my future plans once I am officially released by the ESKS," Joseph said via Twitter on Wednesday. "I have ask for my release because I would like to retire as a member of the ROUGHRIDERS in the near future.
"Please be patient with me over the next few days and then I will give a detailed statement of why I came to this decision. I know mentally and physically I can still play this game but other factors have pushed me away as a player! I will truly miss football as a player but I have so much to give as a coach!"
Joseph spent four seasons in Edmonton, completing 189-of-319 passes (59 per cent) for 2,660 yards with 14 touchdowns and 13 interceptions. He also ran for 384 yards and scored 13 TDs.
"Kerry and I had several conversations throughout the week about the future direction of the club," Eskimos GM Ed Hervey said in a statement. "At that time, he asked for and was granted a release.
"Kerry is a consummate professional. We value his contributions to the team, on and off the field, and wish him the very best in his future endeavours."