The Cleveland Browns have placed linebacker Blake Costanzo, one of their top special teams players, on injured reserve.
Costanzo injured his groin during Sunday's 24-20 loss at Jacksonville. On Monday, coach Eric Mangini said ''it didn't look good.'' On Tuesday, the club placed him on IR. Costanzo has been a mainstay on the Browns' outstanding kick and punt coverage units.
To fill his roster spot, the Browns signed linebacker Eric Alexander, a six-year veteran who has played with New England and Jacksonville. He played in four games for the Jaguars this season before being waived on Nov. 2.
On the practice squad, the Browns waived offensive lineman Jeff Hansen and running back Martell Mallett and signed offensive lineman John Malecki and running back Quinn Porter.