TORONTO - Running back Tyler Ebell, who was attempting to come back from Achilles tendon surgery, was among 21 players released Thursday by the Toronto Argonauts.

CFL teams have to reduce their rosters to 46 players by 3 p.m. ET on Thursday. Clubs can also place up to seven players on their practice rosters as well.

The Argos acquired Ebell and receiver T.J. Acree from Edmonton on Feb. 15, 2008 for cornerback Jordan Younger. Ebell led the Eskimos in rushing (650 yards, 5.2-yard average) and total yards (1,318) in 2007 and was named the club's top rookie.

But his '08 season ended before it began as Ebell suffered a career-threatening ruptured left Achilles tendon during training camp. After an eight-month rehabilitation, Ebell declared himself fit for camp in '09.

But there was no shortage of competition in Toronto's backfield, with incumbent Jamal Robertson, newcomer Jarrett Payton - the son of former NFL legend Walter Payton - and highly touted youngster Da'Shawn Thomas.

The Argos gave Thomas his walking papers Thursday.

Toronto also cut former NFL player Jerome Mathis, who the club was hoping would emerge as its top special-teams returner with the off-season defection of Dominique Dorsey to the NFL's Washington Redskins. Mathis was named to the Pro Bowl during his rookie season with the Houston Texans in 2005.

The other players released include defensive backs Sammy Joseph and Pete Hunter, defensive linemen Kevin Huntley, David McMillan and Ben Ishola, receivers Brad Smith, Cleannord Staintil, Matt Lambros, Kinsmon Lancaster, Ken O'Neal and Todd Lowber, offensive linemen Chris Van Zeyl, Gordon Sawler and Zachary Pollari and quarterback Stephen Reaves.