The Riders added to their defensive line Wednesday by signing international defensive lineman Willie Jefferson.
The 6 foot 6, 245 pound Jefferson comes to the Riders after a tryout with the Washington Redskins where he played three pre-season games.
The 25-year-old signed with Washington in January after two standout seasons with the Edmonton Eskimos. The Beaumont, Texas native registered 43 defensive tackles, 10 quarterback sacks and 10 knockdowns in 35 regular season games.
Jefferson won his first career Grey Cup in 2015 with the Edmonton Eskimos.