It's been a tough year already for linebackers
First, it was Brian Cushing. Then, Ray Lewis.
And, now, Dallas Cowboys linebacker Sean Lee and Carolina Panthers linebacker Jon Beason are done for the season.
The Cowboys placed Lee, an emerging young standout, on injured reserve with torn ligaments in his toe that will require surgery next week.
Former Detroit Lions first-round linebacker Ernie Sims was signed to the roster to replace Lee. Safety Charlie Peprah was added as well with punter Chris Jones heading to injured reserve.
Lee is the Cowboys' leading tackler and defenisve leader.
Sims was with the Indianapolis Colts last season, and tried out for the Tennessee Titans on Tuesday.
He recorded 32 tackles with the Colts after playing one season for the Philadelphia Eagles and registering 55 tackles.
The former Florida State star never lived up to expectations of being a top 10 draft selection in Detroit.
** Meanwhile, the Titans tried out former Maryland and Minnesota Vikings linebacker E.J. Henderson, former Maryland linebacker Adrian Moten, Sims, former New England Patriots and Miami Dolphins linebacker Gary Guyton, former Ravens linebacker Darryl Blackstock, former Eagles linebacker Omar Gaither and former Jacksonville Jaguars linebacker Xavier Adibi.
** Offensive tackle Dominic Alford and center Tyler Horn visited the Titans.
** Defensive back A.J. Davis visited the New Orleans Saints.
** The Panthers tried out former Eagles linebacker Brian Rolle.
** The Detroit Lions worked out defensive end Kendrick Adams, linebacker D.J. Bryant and defensive end Louis Nzegwu.
** The Green Bay Packers tried out guard Nyere Aumaitre, defensive tackle Jamie Cumbie, defensive tackle Jordan Miller, linebacker Quinton Spears, linebacker Nathan Stubar, guard Wayne Tribue and linebacker Jabara Williams.
** The Houston Texans tried out former Panthers second-round defensive tackle Terrell McClain, defensive end Malcolm Sheppard and defensive end Jarius Wynn.
** The Colts tried out tight end LaMark Brown, wide receiver Cody Pearce, wide receiver DeMarco Sampson, offensive tackle J.B. Shugarts and wide receiver Teddy Williams.
** The New England Patriots tried out linebacker Mike Rivera.
** The New York Jets tried out former Maryland tight end Joey Haynos and tight end Colin Cochart.
** The Oakland Raiders tried out defensive end Marcus Benard, guard Jason Foster, offensive tackle A.J. Greene, linebacker Tim Fugger and offensive tackle Jason Slowey, adding Slowey to the practice squad.
** The Eagles tried out and signed center Matt Tennant.
** The Seattle Seahawks tried out defensive backs Mario Butler and Kevin Rutland.
** Former New York Giants safety Janzen Jackson has completed his suspension and is eligible to sign with any team. He has to fulfil all requirements under the NFL steroid and performance-enhancing drug policy to be allowed to play.