I was at a game in 2008, Sask @BC, Week 2. Marcus Crandell was the QB for the Riders. Late 3rd quarter he tweaked his elbow or something and came out of the game, although I suspect that it had more to do with him not moving the offense. After 3 quarters the score was 16-10 Lions and the Riders had 90 yards of offense.
Long story short, some kid named Darian Durant came into the game and put up another 100 yards and Sask won the game 20-16. The next week he was the starter.