He played 179 regular-season games over his CFL career and won a Grey Cup with the Riders in 2007. The 41-year-old pivot came out of retirement last October after regular starter Darian Durant suffered an elbow injury.
Joseph, who won the league's most outstanding player award in 2007, played parts of three seasons (2006-'07, '14) in Saskatchewan. He also spent time with the Ottawa Renegades (2003-'05), Toronto Argonauts (2008-'09) and Edmonton Eskimos (2010-'13).
Joseph's best season in the CFL was arguably the 2005 campaign with the Renegades. That year he set career highs in passing yards (4,466), touchdowns (25) and rushing yards (1,006).
Joseph saw limited action upon his return last season as the Riders struggled in Durant's absence. Saskatchewan finished third in the West at 10-8 and dropped an 18-10 decision to Edmonton in the division semifinal.
Over his 12-year career, Joseph completed 2,061 of 3,532 passes for 28,097 yards. He had 148 touchdown passes and 126 interceptions.
Joseph also scored 57 rushing touchdowns. He rushed the ball 697 times for 4,593 yards (6.6-yard average).